10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q

☒Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the quarterly period ended September 30, 2016

☐Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the transition period from                      to                     .

Commission file number: 001-34877

CoreSite Realty Corporation

(Exact name of registrant as specified in its charter)

Maryland	27-1925611
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
1001 17th Street, Suite 500 Denver, CO	80202
(Address of principal executive offices)	(Zip Code)

(866) 777-2673

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.  Yes ☒  No ☐.

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).  Yes ☒  No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer ☒	Accelerated filer ☐
Non-accelerated filer ☐ (Do not check if a smaller reporting company)	Smaller reporting company ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).  Yes ☐  No ☒

The number of shares of common stock outstanding at October 26, 2016, was 33,895,155.

CORESITE REALTY CORPORATION

FORM 10-Q

FOR THE QUARTER ENDED SEPTEMBER 30, 2016

TABLE OF CONTENTS

	PAGE
	NO.
PART I. FINANCIAL INFORMATION	3
ITEM 1. Financial Statements	3
Condensed Consolidated Balance Sheets as of September 30, 2016, and December 31, 2015 (unaudited)	3
Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2016, and 2015 (unaudited)	4
Condensed Consolidated Statements of Comprehensive Income for the three and nine months ended September 30, 2016, and 2015 (unaudited)	5
Condensed Consolidated Statement of Equity for the nine months ended September 30, 2016 (unaudited)	6
Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2016, and 2015 (unaudited)	7
Notes to Condensed Consolidated Financial Statements (unaudited)	8
ITEM 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations	24
ITEM 3. Quantitative and Qualitative Disclosures About Market Risk	36
ITEM 4. Controls and Procedures	37
PART II. OTHER INFORMATION	38
ITEM 1. Legal Proceedings	38
ITEM 1A. Risk Factors	38
ITEM 2. Unregistered Sales of Equity Securities and Use of Proceeds	38
ITEM 3. Defaults Upon Senior Securities	38
ITEM 4. Mine Safety Disclosures	39
ITEM 5. Other Information	39
ITEM 6. Exhibits	39
Signatures	40
Exhibit 31.1
Exhibit 31.2
Exhibit 32.1
Exhibit 32.2
EX-101 INSTANCE DOCUMENT
EX-101 SCHEMA DOCUMENT
EX-101 CALCULATION LINKBASE DOCUMENT
EX-101 LABELS LINKBASE DOCUMENT
EX-101 PRESENTATION LINKBASE DOCUMENT
EX-101 DEFINITION LINKBASE DOCUMENT

2

PART I — FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

CORESITE REALTY CORPORATION

CONDENSED CONSOLIDATED BALANCE SHEETS

(unaudited and in thousands except share data)

	September 30,		December 31,
	2016		2015
ASSETS
Investments in real estate:
Land	$	82,463	$	74,819
Buildings and improvements		1,186,712		1,037,127
		1,269,175		1,111,946
Less: Accumulated depreciation and amortization		(345,224)		(284,219)
Net investment in operating properties		923,951		827,727
Construction in progress		272,928		183,189
Net investments in real estate		1,196,879		1,010,916
Cash and cash equivalents		6,296		6,854
Accounts and other receivables, net of allowance for doubtful accounts of $97 and $56 as of September 30, 2016, and December 31, 2015, respectively		16,103		12,235
Lease intangibles, net of accumulated amortization of $11,790 and $11,437 as of September 30, 2016, and December 31, 2015, respectively		3,249		4,714
Goodwill		41,191		41,191
Other assets, net		96,274		86,633
Total assets	$	1,359,992	$	1,162,543
LIABILITIES AND EQUITY
Liabilities:
Debt, net of unamortized deferred financing costs of $3,758 and $1,243 as of September30, 2016, and December 31, 2015, respectively	$	590,992	$	391,007
Accounts payable and accrued expenses		86,129		75,783
Accrued dividends and distributions		28,630		28,104
Deferred rent payable		7,577		7,934
Acquired below-market lease contracts, net of accumulated amortization of $5,241 and $5,279 as of September30, 2016, and December 31, 2015, respectively		4,059		4,693
Unearned revenue, prepaid rent and other liabilities		33,444		28,717
Total liabilities		750,831		536,238
Stockholders' equity:
Series A Cumulative Preferred Stock 7.25%, $115,000 liquidation preference ($25.00 per share, $0.01 par value), 4,600,000 shares issued and outstanding as of September 30, 2016, and December 31, 2015		115,000		115,000
Common Stock, par value $0.01, 100,000,000 shares authorized and 33,893,326 and 30,650,703 shares issued and outstanding at September 30, 2016, and December 31, 2015, respectively		334		301
Additional paid-in capital		436,311		390,200
Accumulated other comprehensive loss		(2,141)		(493)
Distributions in excess of net income		(105,756)		(88,891)
Total stockholders' equity		443,748		416,117
Noncontrolling interests		165,413		210,188
Total equity		609,161		626,305
Total liabilities and equity	$	1,359,992	$	1,162,543

See accompanying notes to condensed consolidated financial statements.

3

CORESITE REALTY CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(unaudited and in thousands except share and per share data)

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Operating revenues:
Data center revenue:
Rental revenue	$	54,219	$	47,135	$	156,954	$	133,282
Power revenue		28,844		23,543		80,819		64,782
Interconnection revenue		13,374		11,400		39,093		32,210
Tenant reimbursement and other		2,826		2,357		6,982		6,049
Office, light-industrial and other revenue		2,011		1,947		5,996		6,050
Total operating revenues		101,274		86,382		289,844		242,373
Operating expenses:
Property operating and maintenance		28,283		24,203		78,522		65,965
Real estate taxes and insurance		3,524		3,216		9,659		8,421
Depreciation and amortization		26,981		24,347		77,978		71,209
Sales and marketing		4,465		3,775		13,187		11,813
General and administrative		9,432		8,644		26,970		24,461
Rent		5,967		5,440		16,718		15,690
Transaction costs		117		6		126		51
Total operating expenses		78,769		69,631		223,160		197,610
Operating income		22,505		16,751		66,684		44,763
Gain on real estate disposal		—		—		—		36
Interest income		34		1		35		5
Interest expense		(3,222)		(2,188)		(7,914)		(5,183)
Income before income taxes		19,317		14,564		58,805		39,621
Income tax benefit (expense)		2		(34)		(45)		(149)
Net income	$	19,319	$	14,530	$	58,760	$	39,472
Net income attributable to noncontrolling interests		5,055		5,526		17,031		16,193
NetincomeattributabletoCoreSiteRealtyCorporation	$	14,264	$	9,004	$	41,729	$	23,279
Preferred stock dividends		(2,084)		(2,084)		(6,253)		(6,253)
Net income attributable to common shares	$	12,180	$	6,920	$	35,476	$	17,026
Net income per share attributable to common shares:
Basic	$	0.36	$	0.26	$	1.11	$	0.71
Diluted	$	0.36	$	0.26	$	1.10	$	0.69
Weighted average common shares outstanding
Basic		33,425,762		26,126,332		31,906,000		24,029,106
Diluted		33,912,155		26,549,537		32,361,367		24,544,612

See accompanying notes to condensed consolidated financial statements.

4

CORESITE REALTY CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

(unaudited and in thousands)

	Three Months Ended September30,				Nine Months Ended September30,
	2016		2015		2016		2015
Net income	$	19,319	$	14,530	$	58,760	$	39,472
Other comprehensive income (loss):
Unrealized gain (loss) on derivative contracts		824		(2,947)		(3,597)		(3,807)
Reclassification of other comprehensive income to interest expense		432		567		1,338		1,371
Comprehensive income		20,575		12,150		56,501		37,036
Comprehensive income attributable to noncontrolling interests		5,423		4,469		16,214		15,016
Comprehensive income attributable to CoreSite Realty Corporation	$	15,152	$	7,681	$	40,287	$	22,020

See accompanying notes to condensed consolidated financial statements.

5

CORESITE REALTY CORPORATION

CONDENSED CONSOLIDATED STATEMENT OF EQUITY

(unaudited and in thousands except share data)

								Accumulated
						Additional		Other		Distributions		Total
	Preferred		CommonShares			Paid-in		Comprehensive		in Excess of		Stockholders'		Noncontrolling		Total
	Stock		Number	Amount		Capital		Loss		Net Income		Equity		Interests		Equity
Balance at January 1, 2016	$	115,000	30,650,703	$	301	$	390,200	$	(493)	$	(88,891)	$	416,117	$	210,188	$	626,305
Redemption of noncontrolling interests		—	3,007,000		30		37,550		(206)		—		37,374		(37,374)		—
Issuance of stock awards, net of forfeitures		—	164,014		—		—		—		—		—		—		—
Exercise of stock options, net of settlements		—	71,609		1		1,242		—		—		1,243		—		1,243
Share-based compensation		—	—		2		7,319		—		—		7,321		—		7,321
Dividends declared on preferred stock		—	—		—		—		—		(6,253)		(6,253)		—		(6,253)
Dividends and distributions		—	—		—		—		—		(52,341)		(52,341)		(23,615)		(75,956)
Net income		—	—		—		—		—		41,729		41,729		17,031		58,760
Other comprehensive loss		—	—		—		—		(1,442)		—		(1,442)		(817)		(2,259)
Balance at September 30, 2016	$	115,000	33,893,326	$	334	$	436,311	$	(2,141)	$	(105,756)	$	443,748	$	165,413	$	609,161

See accompanying notes to condensed consolidated financial statements.

6

CORESITE REALTY CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(unaudited and in thousands)

	Nine Months Ended September 30,
	2016		2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$	58,760	$	39,472
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		77,978		71,209
Amortization of above/below market leases		(417)		(387)
Amortization of deferred financing costs		964		999
Gain on real estate disposal		—		(36)
Share-based compensation		6,874		5,305
Bad debt expense		272		310
Changes in operating assets and liabilities:
Accounts receivable		(4,140)		(4,214)
Deferred rent receivable		(1,906)		(5,423)
Deferred leasing costs		(10,534)		(11,242)
Other assets		(8,499)		(4,661)
Accounts payable and accrued expenses		1,413		4,045
Unearned revenue, prepaid rent and other liabilities		2,480		8,799
Deferred rent payable		(356)		(737)
Net cash provided by operating activities		122,889		103,439
CASH FLOWS FROM INVESTING ACTIVITIES
Tenant improvements		(3,487)		(5,356)
Real estate improvements		(234,963)		(72,443)
Escrow deposits		(4,075)		—
Proceeds from real estate disposal		—		2,399
Net cash used in investing activities		(242,525)		(75,400)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from exercise of stock options		1,243		1,171
Proceeds from revolving credit facility		200,250		55,000
Payments on revolving credit facility		(247,750)		(163,250)
Proceeds from unsecured debt		250,000		150,000
Payments of loan fees and costs		(2,981)		(2,315)
Payments to net settle equity awards		—		(4,256)
Dividends and distributions		(81,684)		(65,574)
Net cash provided by (used in) financing activities		119,078		(29,224)
Net change in cash and cash equivalents		(558)		(1,185)
Cash and cash equivalents, beginning of period		6,854		10,662
Cash and cash equivalents, end of period	$	6,296	$	9,477
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for interest, net of capitalized amounts	$	5,912	$	4,501
NON-CASH INVESTING AND FINANCING ACTIVITY
Construction costs payable capitalized to real estate	$	46,048		18,943
Accrual of dividends and distributions	$	28,630	$	22,688

See accompanying notes to condensed consolidated financial statements.

7

CORESITE REALTY CORPORATION

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

September 30, 2016

(unaudited)

1. Organization and Description of Business

CoreSite Realty Corporation (the “Company,” “we,”  “us,” or “our”) was organized in the state of Maryland on February 17, 2010, and is a fully-integrated, self-administered, and self-managed real estate investment trust (“REIT”). Through our controlling interest in CoreSite, L.P. (our “Operating Partnership”), we are engaged in the business of owning, acquiring, constructing and operating data centers. As of September 30, 2016, the Company owns a 70.7% common interest in our Operating Partnership and affiliates of The Carlyle Group and others own a 29.3% interest in our Operating Partnership. See additional discussion in Note 8, Noncontrolling Interests — Operating Partnership.

2. Summary of Significant Accounting Policies

Principles of Consolidation and Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared by our management in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and in compliance with the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, these unaudited condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of our management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. The results of operations for the three and nine months ended September 30, 2016, are not necessarily indicative of the expected results for the year ending December 31, 2016. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2015. Intercompany balances and transactions have been eliminated upon consolidation.

In 2016, we adopted ASU 2015-02, Amendments to the Consolidation Analysis. This standard amends certain guidance applicable to the consolidation of various legal entities, including variable interest entities (“VIE”). We evaluated the application of ASU 2015-02 and concluded that no change was required to the accounting for our interest in our Operating Partnership. However, under the new guidance, our Operating Partnership now meets the definition and criteria of a VIE and we are the primary beneficiary of the VIE. Our sole significant asset is the investment in our Operating Partnership, and consequently, substantially all of our assets and liabilities represent those assets and liabilities of our Operating Partnership. Our debt is an obligation of our Operating Partnership where the creditors also have recourse against the credit of the Company.

Recent Accounting Pronouncements

In August 2016, the Financial Accounting Standards Board (“FASB”) issued guidance codified in Accounting Standards Codification (“ASC”) Topic 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The standard provides guidance on eight specific cash flow classification issues including debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, and separately identifiable cash flows and application of the predominance principle. The standard will be effective for the fiscal year beginning January 1, 2018, and subsequent interim periods. We do not expect the provisions of ASC 2016-15 to have a material impact on our consolidated financial statements.

In March 2016, the Financial Accounting Standards Board (“FASB”) issued guidance codified in Accounting Standards Codification (“ASC”) Topic 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The standard simplifies several aspects related to the accounting for share-based payment transactions, including the accounting for income taxes, statutory tax withholding requirements and classification on the statement of cash flows. The standard will be effective for the fiscal year beginning January 1, 2017 and subsequent interim periods. We do not expect the provisions of ASC 2016-09 to have a material impact on our consolidated financial statements.

8

In February 2016, the FASB issued guidance codified in ASC Topic 842, Leases, which amends the guidance in former ASC 840, Leases. The standard is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted. The standard requires a modified retrospective transition approach. We are currently evaluating the impact of the provisions of ASC 842 on our lessee and lessor accounting policies and consolidated financial statements.

In May 2014, the FASB issued guidance codified in ASC Topic 606, Revenue Recognition — Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition. The standard is effective for interim and annual reporting periods beginning after December 15, 2017. The standard permits the use of either the retrospective or cumulative effect transition method. We are currently evaluating the impact of the provisions of ASC 606 on our revenue recognition policies as well as the transition method to be used to implement this guidance.

Use of Estimates

The preparation of these unaudited condensed consolidated financial statements in conformity with GAAP requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingencies at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. We evaluate our estimates, including those related to assessing the carrying values of our real estate properties, goodwill, accrued liabilities and performance-based equity compensation plans. We base our estimates on historical experience, current market conditions, and various other assumptions that we believe to be reasonable under the circumstances. Actual results may vary from those estimates and those estimates could vary under different assumptions or conditions.

Adjustments and Reclassifications

Certain immaterial adjustments have been made to the condensed consolidated financial statements for 2015 to conform to the 2016 financial statement presentation.

Investments in Real Estate

Real estate investments are carried at cost less accumulated depreciation and amortization. The cost of real estate includes the purchase price of property and leasehold improvements. Expenditures for maintenance and repairs are expensed as incurred. Significant renovations and betterments that extend the economic useful lives of assets are capitalized. During land development and construction periods, we capitalize construction costs, legal fees, financing costs, real estate taxes and insurance, rental expense and internal costs of personnel performing development, if such costs are incremental and identifiable to a specific development project. Capitalization of costs begins upon commencement of development efforts and ceases when the property is ready for its intended use and held available for occupancy. Interest is capitalized during the period of development based upon applying the weighted-average borrowing rate to the actual development costs expended. Capitalized interest costs were $1.6 million and $0.6 million for the three months ended September 30, 2016, and 2015, respectively, and $3.5 million and $2.9 million for the nine months ended September 30, 2016, and 2015, respectively.

Depreciation and amortization are calculated using the straight-line method over the following useful lives of the assets:

Buildings	27 to 40 years
Building improvements	1 to 10 years
Leasehold improvements	The shorter of the lease term or useful life of the asset

Depreciation expense was $22.3 million and $19.6 million for the three months ended September 30, 2016, and 2015, respectively, and $63.9 million and $56.7 million for the nine months ended September 30, 2016, and 2015, respectively.

Acquisition of Investment in Real Estate

Purchase accounting is applied to the assets and liabilities related to all real estate investments acquired. The fair value of the real estate acquired is allocated to the acquired tangible assets, consisting primarily of land, building and building improvements, and identified intangible assets and liabilities, consisting of the value of above-market and below-market leases, value of in-place leases and the value of customer relationships.

9

The fair value of the land and building of an acquired property is determined by valuing the property as if it were vacant, and the “as-if-vacant” fair value is then allocated to land and building based on management's determination of the fair values of these assets. Management determines the as-if-vacant fair value of a property using methods similar to those used by independent appraisers. Factors considered by management in performing these analyses include an estimate of carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases.

The fair value of intangibles related to in-place leases includes the value of lease intangibles for above-market and below-market leases, lease origination costs, and customer relationships, determined on a lease-by-lease basis. Above-market and below-market leases are valued based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) management's estimate of fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining noncancelable term of the lease and, for below-market leases, over a period equal to the initial term plus any below-market fixed rate renewal periods. Lease origination costs include estimates of costs avoided associated with leasing the property, including tenant allowances and improvements and leasing commissions. Customer relationship intangibles relate to the additional revenue opportunities expected to be generated through interconnection services and utility services to be provided to the in-place lease tenants.

The capitalized values for above and below-market lease intangibles, lease origination costs, and customer relationships are amortized over the term of the underlying leases or the expected customer relationship. Amortization related to above-market and below-market leases where the Company is the lessor is recorded as either a reduction of or an increase to rental revenue, amortization related to above-market and below-market leases where the Company is the lessee is recorded as either a reduction of or an increase to rent expense. If a lease is terminated prior to its stated expiration, all unamortized amounts relating to that lease are written off.

The carrying value of intangible assets is reviewed for impairment in connection with its respective asset group whenever events or changes in circumstances indicate that the asset group may not be recoverable. An impairment loss is recognized if the carrying amount of the asset group is not recoverable and its carrying amount exceeds its estimated fair value. No impairment loss related to these intangible assets was recognized for the three or nine months ended September 30, 2016, or 2015.

The excess of the cost of an acquired business over the net of the amounts assigned to assets acquired (including identified intangible assets) and liabilities assumed is recorded as goodwill. As of September 30, 2016, and December 31, 2015, we had approximately $41.2 million of goodwill at each date. The Company’s goodwill has an indeterminate life and is not amortized, but is tested for impairment on an annual basis, or more frequently if events or changes in circumstances indicate that the asset might be impaired. No impairment loss was recognized for the three or nine months ended September 30, 2016, or 2015.

Cash and Cash Equivalents

Cash and cash equivalents include all non-restricted cash held in financial institutions and other non-restricted highly liquid short-term investments with original maturities at acquisition of three months or less.

10

Deferred Costs

Deferred leasing costs include commissions paid to third parties, including brokers, leasing agents, referral agents, and internal sales commissions paid to employees for successful execution of lease agreements. These commissions and other direct and incremental costs incurred to obtain new customer leases are capitalized and amortized over the lease terms of the related leases using the straight-line method. If a lease terminates prior to the expiration of its initial term, any unamortized deferred costs related to the lease are written off to amortization expense. Deferred leasing costs are included within other assets in the condensed consolidated balance sheets and consisted of the following, net of amortization, as of September 30, 2016, and December 31, 2015 (in thousands):

	September 30,		December 31,
	2016		2015
Internal sales commissions	$	18,678	$	17,558
Third party commissions		13,910		15,866
External legal counsel		740		718
Total	$	33,328	$	34,142

Deferred financing costs include costs incurred in connection with obtaining debt and extending existing debt. These financing costs are capitalized and amortized on a straight-line basis, which approximates the effective-interest method, over the term of the loan and the amortization is included as a component of interest expense. Depending on the type of debt instrument, deferred financing costs are reported either in other assets or as a direct deduction from the carrying amount of the related debt liabilities in our condensed consolidated balance sheets.

Recoverability of Long-Lived Assets

We review our long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Impairment is recognized when estimated expected future cash flows (undiscounted and without interest charges) are less than the carrying amount of the assets. The estimation of expected future net cash flows is inherently uncertain and relies, to a considerable extent, on assumptions regarding current and future economics and market conditions and the availability of capital. If, in future periods, there are changes in the estimates or assumptions incorporated into the impairment review analysis, the changes could result in an adjustment to the carrying amount of the long-lived assets. To the extent that impairment has occurred, the excess of the carrying amount of long-lived assets over its estimated fair value would be recognized as an impairment loss charged to net income. For the three and nine months ended September 30, 2016, and 2015, no impairment of long-lived assets was recognized.

Derivative Instruments and Hedging Activities

We reflect all derivative instruments at fair value as either assets or liabilities on the condensed consolidated balance sheets. For those derivative instruments that are designated and qualify as hedging instruments, we record the effective portion of the gain or loss on the hedging instruments as a component of accumulated other comprehensive income or loss. Any ineffective portion of a derivative's change in fair value is immediately recognized within net income. For derivatives that do not meet the criteria for hedge accounting, changes in fair value are immediately recognized within net income. See additional discussion in Note 6, Derivatives and Hedging Activities.

Internal-Use Software

We recognize internal-use software development costs based on the development stage of the project and nature of the cost. Internal and external costs incurred during the preliminary project stage are expensed as they are incurred. Internal and external costs incurred to develop internal-use software during the application development stage are capitalized. Internal and external training costs and maintenance costs during the post-implementation-operation stage are expensed as incurred. Completed projects are placed into service and amortized over the estimated useful life of the software. No impairment was recognized related to internal-use software in the condensed consolidated statements of operations for the three or nine months ended September 30, 2016, and 2015.

11

Revenue Recognition

All customer leases are classified as operating leases and minimum rents are recognized on a straight-line basis over the customer’s lease term. The excess of rents recognized over amounts contractually due pursuant to the underlying leases are included in deferred rent receivable and included in other assets in the condensed consolidated balance sheets.  If a lease terminates prior to its stated expiration, the deferred rent receivable relating to that lease is written off as a reduction of rental revenue.

When arrangements include multiple elements, the revenue associated with separate elements is allocated based on the relative fair values of those elements. The revenue associated with each element is then recognized as earned. Interconnection services and additional space services are considered as separate earnings processes that are provided and completed on a month-to-month basis and revenue is recognized in the period that services are performed. Customer set-up charges and utility installation fees are initially deferred and recognized over the term of the arrangement as revenue.

Tenant reimbursements for real estate taxes, common area maintenance, and other recoverable costs are recognized as revenue in the period that the related expenses are incurred.

Above-market and below-market lease intangibles that were acquired are amortized on a straight-line basis as decreases and increases, respectively, to rental revenue over the remaining noncancelable term of the underlying leases. For both the three months ended September 30, 2016, and 2015, the net effect of amortization of acquired above-market and below-market leases resulted in an increase to rental revenue of $0.1 million. For both the nine months ended September 30, 2016, and 2015, the net effect of amortization of acquired above-market and below market leases resulted in an increase to rental revenue of $0.4 million.

A provision for uncollectible accounts is recorded if a receivable balance relating to contractual rent, rent recorded on a straight-line basis, tenant reimbursements or other billed amounts is considered by management to be uncollectible. At both September 30, 2016, and December 31, 2015, the allowance for doubtful accounts totaled $0.1 million.

Share-Based Compensation

We account for share-based compensation using the fair value method of accounting. The estimated fair value of the stock options granted by us is calculated based on the Black-Scholes option-pricing model. The fair value of restricted share-based and Operating Partnership unit compensation is based on the fair value of our common stock on the date of the grant. The fair value of performance share awards, which have a market condition, is based on a Monte Carlo simulation. The fair value for all share-based compensation is amortized on a straight-line basis over the vesting period.

Asset Retirement and Environmental Remediation Obligations

We record accruals for estimated asset retirement and environmental remediation obligations. The obligations relate primarily to the removal of asbestos during development of properties as well as the estimated equipment removal costs upon termination of a certain lease where we are the lessee. At September 30, 2016, and December 31, 2015, the amounts included in unearned revenue, prepaid rent and other liabilities on the condensed consolidated balance sheets were approximately $1.4 million and $1.7 million, respectively.

Income Taxes

We elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”), commencing with our taxable year ended December 31, 2010. To qualify as a REIT, we are required to distribute at least 90% of our taxable income to our stockholders and meet various other requirements imposed by the Code relating to such matters as operating results, asset holdings, distribution levels and diversity of stock ownership. Provided we qualify for taxation as a REIT, we generally are not subject to corporate level federal income tax on the earnings distributed currently to our stockholders. If we fail to qualify as a REIT in any taxable year, and are unable to avail ourselves of certain savings provisions set forth in the Code, all of our taxable income would be subject to federal income tax at regular corporate rates, including any applicable alternative minimum tax.

12

To maintain REIT status, we must distribute a minimum of 90% of our taxable income. However, it is our policy and intent, subject to change, to distribute 100% of our taxable income and therefore no provision is required in the accompanying condensed consolidated financial statements for federal income taxes with regards to activities of the REIT and its subsidiary pass-through entities. The allocable share of taxable income is included in the income tax returns of its stockholders. The Company is subject to the statutory requirements of the locations in which it conducts business. State and local income taxes are accrued as deemed required in the best judgment of management based on analysis and interpretation of respective tax laws.

We have elected to treat certain subsidiaries as taxable REIT subsidiaries (“TRS”). Certain activities that we undertake must be conducted by a TRS, such as services for our tenants that could be considered otherwise impermissible for us to perform and holding assets that we cannot hold directly. A TRS is subject to corporate level federal and state income taxes.

Deferred income taxes are recognized in certain taxable entities. Deferred income tax generally is a function of the period's temporary differences (items that are treated differently for tax purposes than for financial reporting purposes), the utilization of tax net operating losses generated in prior years that previously had been recognized as deferred income tax assets and the reversal of any previously recorded deferred income tax liabilities. A valuation allowance for deferred income tax assets is provided if we believe all or some portion of the deferred income tax asset may more likely than not realized. Any increase or decrease in the valuation allowance resulting from a change in circumstances that causes a change in the estimated realizability of the related deferred income tax asset is included in deferred tax expense. As of September 30, 2016, and December 31, 2015, the gross deferred income taxes were not material.

We currently have no liabilities for uncertain income tax positions. The earliest tax year for which we are subject to examination is 2013.

Concentration of Credit Risks

Our cash and cash equivalents are maintained in various financial institutions, which, at times, may exceed federally insured limits. We have not experienced any losses in such accounts, and management believes that the Company is not exposed to any significant credit risk in this area. We have no off-balance sheet concentrations of credit risk, such as foreign exchange contracts, option contracts, or foreign currency hedging arrangements.

Segment Information

We manage our business as one reportable segment consisting of investments in data centers located in the United States. Although we provide services in several markets, these operations have been aggregated into one reportable segment based on the similar economic characteristics amongst all markets, including the nature of the services provided and the type of customers purchasing these services.

3. Investment in Real Estate

The following is a summary of the properties owned or leased by market at September 30, 2016 (in thousands):

			Buildings and		Construction in
Market	Land		Improvements		Progress		Total Cost
Boston	$	5,154	$	96,202	$	459	$	101,815
Chicago		5,493		98,549		2,159		106,201
Denver		—		4,878		2,068		6,946
Los Angeles		28,467		232,825		3,439		264,731
Miami		728		10,482		2		11,212
New York		2,388		127,842		38,096		168,326
Northern Virginia		12,442		246,606		7,380		266,428
San Francisco Bay		27,791		369,328		219,325		616,444
Total	$	82,463	$	1,186,712	$	272,928	$	1,542,103

13

4. Other Assets

Our other assets consisted of the following, net of amortization and depreciation, if applicable, as of September 30, 2016, and December 31, 2015 (in thousands):

	September 30,		December 31,
	2016		2015
Deferred leasing costs	$	33,328	$	34,142
Deferred rent receivable		31,215		29,309
Internal-use software		13,010		10,467
Prepaid expenses		6,415		2,689
Corporate furniture, fixtures and equipment		5,556		6,157
Deferred financing costs		1,766		2,251
Other		4,984		1,618
Total	$	96,274	$	86,633

5. Debt

A summary of outstanding indebtedness as of September 30, 2016, and December 31, 2015, is as follows (in thousands):

		Maturity	September 30,		December 31,
	Interest Rate	Date	2016		2015
Revolving credit facility	2.08% and 1.98% at September 30, 2016, and December 31, 2015, respectively	June 24, 2019	$	94,750	$	142,250
2019 Senior unsecured term loan(1)	3.23% at September 30, 2016, and December 31, 2015	January 31, 2019		100,000		100,000
2020 Senior unsecured term loan(2)	2.48% and 2.43% at September 30, 2016, and December 31, 2015	June 24, 2020		150,000		150,000
2021 Senior unsecured term loan	2.03% at September 30, 2016	February 2, 2021		100,000		—
2023 Senior unsecured notes	4.19% at September 30, 2016	June 15, 2023		150,000		—
Total principal outstanding				594,750		392,250
Unamortized deferred financing costs				(3,758)		(1,243)
Total debt			$	590,992	$	391,007

(1) Our Operating Partnership entered into a swap agreement with respect to the 2019 Term Loan (as defined below) to swap the variable interest rate associated with $100 million, or 100%, of the 2019 Term Loan to a fixed rate of approximately 3.23% per annum at our current leverage ratio. See Note 6 – Derivatives and Hedging Activities.

(2) Our Operating Partnership entered into a swap agreement with respect to the 2020 Term Loan (as defined below) to swap the variable interest rate associated with $75 million, or 50%, of the principal amount of the 2020 Term Loan to a fixed rate of approximately 2.93% per annum at our current leverage ratio. The interest rate on the remaining $75 million of the 2020 Term Loan is based on LIBOR plus the applicable spread. The effective interest rate as of September 30, 2016, is 2.48%. See Note 6 – Derivatives and Hedging Activities.

Revolving Credit Facility

On June 24, 2015, our Operating Partnership and certain subsidiary co-borrowers entered into a third amended and restated credit agreement (as amended, the “Credit Agreement”) with a group of lenders for which KeyBank National Association acts as the administrative agent. The Credit Agreement amended our Operating Partnership’s second amended and restated unsecured revolving credit facility, dated January 3, 2013 (as amended, the “Prior Facility”). The Credit Agreement maturity date is June 24, 2019, with a one-time extension option, which, if exercised, would extend the maturity date to June 24, 2020. The exercise of the extension option is subject to the payment of an extension fee equal to 10 basis points of the total commitment under the Credit Agreement at initial maturity and certain other customary conditions. The Credit Agreement increased the commitment of $405 million from the Prior Facility to $500 million, providing for a $350 million revolving credit facility and a $150 million unsecured term loan scheduled to mature on June 24, 2020. See “2020 Senior Unsecured Term Loan” below for a discussion of the $150 million term loan. The Credit Agreement contains an accordion feature, which allows our Operating Partnership to increase the total

14

commitment from $500 million to $700 million, under specified circumstances, including securing capital from new or existing lenders.

On February 2, 2016, we partially exercised the Credit Agreement accordion feature and entered into a $100 million senior unsecured term loan, which increased our current commitment under the Credit Agreement from $500 million to $600 million. In addition, the accordion feature increased by $100 million, which allows our Operating Partnership to increase the total commitment from $600 million to $800 million under specified circumstances, including securing capital from new or existing lenders. See “2021 Unsecured Term Loan” below for a discussion of the $100 million senior unsecured term loan.

Borrowings under the revolving credit facility bear interest at a variable rate per annum equal to either (i) LIBOR plus 155 basis points to 225 basis points, or (ii) a base rate plus 55 basis points to 125 basis points, each depending on our Operating Partnership’s leverage ratio. At September 30, 2016, our Operating Partnership’s leverage ratio was 20.7% and the interest rate was LIBOR plus 155 basis points.

The total amount available for borrowing under the revolving credit facility, which is part of the Credit Agreement, is equal to the lesser of $350.0 million or the availability calculated based on our unencumbered asset pool. As of September 30, 2016, the borrowing capacity was $350.0 million. As of September 30, 2016, $94.8 million was borrowed and outstanding, $4.5 million was outstanding under letters of credit and therefore $250.8 million remained available for us to borrow under the revolving credit facility.

Our ability to borrow under the Credit Agreement is subject to ongoing compliance with a number of financial covenants and other customary restrictive covenants, including, among others:

· a maximum leverage ratio (defined as total consolidated indebtedness to total gross asset value) of 60%, which, as of September 30, 2016, was 20.7%;

· a maximum secured debt ratio (defined as total consolidated secured debt to total gross asset value) of 40%, which, as of September 30, 2016, was 0%;

· a minimum fixed charge coverage ratio (defined as adjusted consolidated earnings before interest, taxes, depreciation and amortization to consolidated fixed charges) of 1.7 to 1.0, which, as of September 30, 2016, was 8.1 to 1.0; and

· a maximum unhedged variable rate debt ratio (defined as unhedged variable rate indebtedness to gross asset value) of 30%, which, as of September 30, 2016, our unhedged variable rate debt ratio was 9.3%.

As of September 30, 2016, we were in compliance with all of the covenants under the Credit Agreement.

2019 Senior Unsecured Term Loan

On January 31, 2014, our Operating Partnership and certain subsidiaries entered into a $100 million senior unsecured term loan (as amended, the “2019 Term Loan”). The 2019 Term Loan has a five-year term and contains an accordion feature, which allows our Operating Partnership to increase the total commitments by $100 million, to $200 million, under specified circumstances, including securing capital from new or existing lenders. The 2019 Term Loan ranks pari passu with the 2020 Term Loan, the 2021 Term Loan, the 2023 Notes and the Credit Agreement and contains the same financial covenants and other customary restrictive covenants. As of September 30, 2016, we were in compliance with all of the covenants under the 2019 Term Loan.

The borrowings under the 2019 Term Loan bear interest at a variable rate per annum equal to either (i) LIBOR plus 175 basis points to 265 basis points, or (ii) a base rate plus 75 basis points to 165 basis points, each depending on our Operating Partnership's leverage ratio. At September 30, 2016, our Operating Partnership’s leverage ratio was 20.7% and the interest rate was LIBOR plus 175 basis points. 

2020 Senior Unsecured Term Loan

On June 24, 2015, in connection with, and pursuant to the terms of, the Credit Agreement, our Operating Partnership and certain subsidiaries entered into a $150 million senior unsecured term loan (the “2020 Term Loan”). The 2020 Term Loan has a five-year term maturing on June 24, 2020. The 2020 Term Loan ranks pari passu with the 2019 Term Loan, the 2021 Term Loan, the 2023 Notes and the Credit Agreement and contains the same financial covenants and other

15

customary restrictive covenants. As of September 30, 2016, we were in compliance with all of the covenants under the 2020 Term Loan.

The borrowings under the 2020 Term Loan bear interest at a variable rate per annum equal to either (i) LIBOR plus 150 basis points to 220 basis points, or (ii) a base rate plus 50 basis points to 120 basis points, each depending on our Operating Partnership's leverage ratio. At September 30, 2016, our Operating Partnership’s leverage ratio was 20.7% and the interest rate was LIBOR plus 150 basis points. 

2021 Senior Unsecured Term Loan

On February 2, 2016, pursuant to the terms of the Credit Agreement, we partially exercised the accordion feature and entered into a $100 million senior unsecured term loan (the “2021 Term Loan”). The 2021 Term Loan has a five-year term maturing on February 2, 2021. The 2021 Term Loan ranks pari passu with the 2019 Term Loan, the 2020 Term Loan, the 2023 Notes and the Credit Agreement and contains the same financial covenants and other customary restrictive covenants. As of September 30, 2016, we were in compliance with all of the covenants under the 2021 Term Loan.

The borrowings under the 2021 Term Loan bear interest at a variable rate per annum equal to either (i) LIBOR plus 150 basis points to 220 basis points, or (ii) a base rate plus 50 basis points to 120 basis points, each depending on our Operating Partnership’s leverage ratio. At September 30, 2016, our Operating Partnership’s leverage ratio was 20.7% and the interest rate was LIBOR plus 150 basis points.

2023 Senior Unsecured Notes

On June 15, 2016, our Operating Partnership issued an aggregate principal amount of $150 million, 4.19% senior unsecured notes due June 15, 2023 (the “2023 Notes”) in a private placement to certain accredited investors. The terms of the 2023 Notes are governed by a note purchase agreement, dated June 15, 2016 (the “Note Purchase Agreement”), by and among our Operating Partnership, the Company and the purchasers named therein.

Interest is payable semiannually, on the 15th day of June and December in each year, commencing on December 15, 2016. The 2023 Notes are senior unsecured obligations of our Operating Partnership and are jointly and severally guaranteed by the Company and each of our Operating Partnership’s subsidiaries that guarantees indebtedness under our Operating Partnership’s Credit Agreement (the “Subsidiary Guarantors”).

Our Operating Partnership may prepay all or a portion of the 2023 Notes upon notice to the holders for 100% of the principal amount so prepaid plus a make-whole premium as set forth in the Note Purchase Agreement. Upon the occurrence of certain change of control events, holders of the 2023 Notes will have the right to require our Operating Partnership to purchase 100% of such holder’s 2023 Notes in cash at a purchase price equal to 100% of the principal amount thereof plus accrued and unpaid interest, if any, to the date of repurchase.

The 2023 Notes rank pari passu with the 2019 Term Loan, the 2020 Term Loan, the 2021 Term Loan and the Credit Agreement. The Note Purchase Agreement contains the same financial covenants as the Credit Agreement, as described above. In addition, certain additional financial covenants in the Credit Agreement were automatically incorporated into the Note Purchase Agreement, and, subject to certain conditions, these additional financial covenants will be deleted, removed, amended or otherwise modified to be more or less restrictive if the analogous covenant in the Credit Agreement is so deleted, removed, amended or otherwise modified. The aforementioned covenants are subject to a number of exceptions and qualifications set forth in the Note Purchase Agreement. As of September 30, 2016, we were in compliance with all of the covenants under the Note Purchase Agreement. 

16

Debt Maturities

The following table summarizes the amount of our outstanding debt as of September 30, 2016, based on when such debt currently becomes due (in thousands):

Year Ending December 31,
Remainder of 2016	$	—
2017		—
2018		—
2019		194,750
2020		150,000
Thereafter		250,000
Total principal outstanding		594,750
Unamortized deferred financing costs		(3,758)
Total debt, net	$	590,992

6. Derivatives and Hedging Activities

On April 9, 2015, we entered into a $75 million forward starting five-year interest rate swap agreement, effective May 5, 2015, to protect against adverse fluctuation in interest rates. The swap reduces our exposure to variability in cash flows relating to interest payments on $75 million of one-month LIBOR variable rate debt and effectively fixes the interest rate at approximately 2.93% per annum. Also, on February 3, 2014, we entered into a five-year interest rate swap agreement that effectively fixes the interest rate on $100 million of outstanding debt at approximately 3.23% per annum. Both interest rate swap agreements were designated for hedge accounting.

Risk Management Objective of Using Derivatives

We are exposed to certain risks arising from both our business operations and economic conditions. We principally manage our exposures to a wide variety of business and operational risks through management of our core business activities. We manage economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of our debt funding and the use of derivative financial instruments. Specifically, we enter into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known or uncertain cash amounts, the value of which are determined by interest rates. Our derivative financial instruments are used to manage differences in the amount, timing, and duration of our known or expected cash receipts and our known or expected cash payments principally related to our investments and borrowings.

Cash Flow Hedges of Interest Rate Risk

Our objectives in using interest rate derivatives are to reduce variability in interest expense and to manage our exposure to adverse interest rate movements. To accomplish this objective, we primarily use interest rate swaps as part of our interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount.

The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income or loss on the condensed consolidated balance sheets and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The amounts recorded in other comprehensive income related to the unrealized loss or gain on derivative contracts were a gain of $0.8 million and a loss of $2.9 million for the three months ended September 30, 2016, and 2015, respectively, and a loss of $3.6 million and $3.8 million for the nine months ended September 30, 2016, and 2015, respectively. The amounts reclassified from other comprehensive income to interest expense on the condensed consolidated statements of operations were $0.4 million and $0.6 million for the three months ended September 30, 2016, and 2015, respectively, and $1.3 million and $1.4 million for the nine months ended September 30, 2016, and 2015, respectively. The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings. During the three and nine months ended September 30, 2016, and 2015, we did not record any amount in earnings related to derivatives as there was no hedge ineffectiveness.

17

Amounts reported in accumulated other comprehensive loss related to derivatives will be reclassified to interest expense as interest payments are made on our variable-rate debt. During the subsequent twelve months, beginning October 1, 2016, we estimate that $1.7 million will be reclassified as an increase to interest expense.

Derivatives are recorded at fair value in our condensed consolidated balance sheets in other assets or unearned revenue, prepaid rent and other liabilities, as applicable. We do not net our derivative position by counterparty for purposes of balance sheet presentation and disclosure. We had $3.0 million and $0.8 million in derivative liabilities recognized in unearned revenue, prepaid rent and other liabilities in our condensed consolidated balance sheets as of September 30, 2016, and December 31, 2015, respectively.

7. Stockholders’ Equity

We declared the following dividends per share on our Series A cumulative preferred stock and common stock during the nine months ended September 30, 2016:

Declaration Date	Record Date	Payment Date	Preferred Stock			Common Stock
March 3, 2016	March 31, 2016	April 15, 2016	$	0.4531	(1)	$	0.53
May 20, 2016	June 30, 2016	July 15, 2016		0.4531	(2)		0.53
September 2, 2016	September 30, 2016	October 17, 2016		0.4531	(3)		0.53
			$	1.3593		$	1.59

(1) Dividend covers the period from January 15, 2016, to April 14, 2016.

(2) Dividend covers the period from April 15, 2016, to July 14, 2016.

(3) Dividend covers the period from July 15, 2016, to October 14, 2016.

8. Noncontrolling Interests — Operating Partnership

Noncontrolling interests represent the limited partnership interests in our Operating Partnership held by individuals and entities other than CoreSite Realty Corporation. The current holders of common Operating Partnership units are eligible to have the common Operating Partnership units redeemed for cash or common stock on a one-for-one basis, at our option.

In connection with the issuance of our 7.25% Series A cumulative redeemable preferred stock on December 12, 2012, our Operating Partnership issued 4,600,000 7.25% Series A cumulative redeemable preferred Operating Partnership units to us. Preferred Operating Partnership units rank senior to the common Operating Partnership units held by both us and noncontrolling interests.

The following table shows the ownership interests in our Operating Partnership as of September 30, 2016, and December 31, 2015:

	September 30, 2016			December 31, 2015
	Number of Units	Percentage of Total		Number of Units	Percentage of Total
CoreSite Realty Corporation	33,371,340	70.7	%	30,136,556	64.1	%
Noncontrolling interests	13,851,347	29.3		16,858,347	35.9
Total	47,222,687	100.0	%	46,994,903	100.0	%

For each share of common stock issued by us, our Operating Partnership issues to us an equivalent common Operating Partnership unit. During the nine months ended September 30, 2016, we issued 227,784 shares of common stock related to employee compensation arrangements and therefore an equivalent number of common Operating Partnership units were issued to us by our Operating Partnership.

Holders of common Operating Partnership units of record as of September 30, 2016, received quarterly distributions of $0.53 per unit, payable in correlation with declared dividends on common stock.

During the nine months ended September 30, 2016, 3,007,000 common Operating Partnership units held by The Carlyle Group and other third parties were redeemed for shares of our common stock in connection with the sale of 3,007,000

18

shares of our common stock. This redemption was recorded as a $37.4 million reduction to noncontrolling interests in our Operating Partnership and an increase to total stockholder’s equity in the condensed consolidated balance sheets.

The redemption value of the noncontrolling interests at September 30, 2016, was $1.0 billion based on the closing price of the Company’s common stock of $74.04 on that date.

9. Equity Incentive Plan

Our Board of Directors adopted and, with the approval of our stockholders, amended the 2010 Equity Incentive Plan (as amended, the “2010 Plan”). The 2010 Plan is administered by the Compensation Committee of the Board of Directors. Awards issuable under the 2010 Plan include common stock, stock options, restricted stock, stock appreciation rights, dividend equivalents, Operating Partnership units and other incentive awards. We have reserved a total of 6,000,000 shares of our common stock for issuance pursuant to the 2010 Plan, which may be adjusted for changes in our capitalization and certain corporate transactions. To the extent that an award expires, terminates or lapses, or an award is settled in cash without the delivery of shares of common stock to the participant, then any unvested shares subject to the award will be available for future grant or sale under the 2010 Plan. Shares of restricted stock which are forfeited or repurchased by us pursuant to the 2010 Plan may again be awarded under the 2010 Plan. The payment of dividend equivalents in cash in conjunction with any outstanding awards will not be counted against the shares available for issuance under the 2010 Plan.

As of September 30, 2016, 3,109,969 shares of our common stock were available for issuance pursuant to the 2010 Plan.

Stock Options

Stock option awards are granted with an exercise price equal to the closing market price of the Company’s common stock on the date of grant. The fair value of each option granted under the 2010 Plan is estimated on the date of grant using the Black-Scholes option-pricing model. The fair values are amortized on a straight-line basis over the vesting periods.

The following table sets forth stock option activity under the 2010 Plan for the nine months ended September 30, 2016:

	Number of
	Shares	Weighted-
	Subject to	Average
	Option	Exercise Price
Options outstanding, December 31, 2015	340,210	$	21.77
Granted	—		—
Exercised	(71,609)		17.35
Forfeited	—		—
Expired	—		—
Options outstanding, September 30, 2016	268,601	$	22.95

The following table sets forth the number of shares subject to options that are unvested as of September 30, 2016, and the fair value of these options at the grant date:

	Number of	Weighted-
	Shares	Average Fair
	Subject to	Value at Grant
	Option	Date
Unvested balance, December 31, 2015	105,267	$	9.13
Granted	—		—
Forfeited	—		—
Vested	(88,944)		8.97
Unvested balance, September 30, 2016	16,323	$	9.99

As of September 30, 2016, total unearned compensation on options was approximately $0.1 million, and the weighted-average vesting period was 0.4 years.

19

Restricted Awards and Units

Restricted stock awards and restricted stock units, or RSUs, are granted with a fair value equal to the closing market price of the Company’s common stock on the date of grant. The principal difference between restricted stock awards and RSUs is that RSUs are not shares of our common stock and do not have any of the rights or privileges thereof, including voting rights. On the applicable vesting date, the holder of an RSU becomes entitled to a share of common stock. The restricted stock awards and RSUs are amortized on a straight-line basis to expense over the vesting period. The following table sets forth the number of unvested restricted stock awards and RSUs and the weighted-average fair value of these awards at the date of grant:

		Weighted-
	Restricted	Average Fair
	Awards and	Value at Grant
	Units	Date
Unvested balance, December 31, 2015	377,612	$	38.51
Granted	179,511		66.69
Forfeited	(35,046)		53.86
Vested	(196,708)		36.62
Unvested balance, September 30, 2016	325,369	$	53.55

As of September 30, 2016, total unearned compensation on restricted awards was approximately $13.9 million, and the weighted-average vesting period was 2.6 years.

Performance Stock Awards

We grant long-term incentives to members of management in the form of performance-based restricted stock awards (“PSAs”) under the 2010 Plan. The number of PSAs earned is based on our achievement of relative total shareholder return (“TSR”) measured versus the MSCI US REIT Index over a three-year performance period and ranges between 0% and 150% of a target number of shares for PSAs granted in 2014 and between 25% and 175% of the target for PSAs granted in 2015 and 2016. The PSAs are granted at the maximum percentage of target and are retired annually to the extent we do not achieve maximum relative TSR versus the MSCI US REIT Index. The PSAs are earned upon TSR achievement measured both annually and over the full three-year performance period. The PSAs have a service condition and will be released at the end of the three-year performance period, to the extent earned, provided that the holder continues to be employed by the Company at the end of the three-year performance period. Holders of the PSAs are entitled to dividends on the PSAs, which will be accrued and paid in cash at the end of the three-year performance period. During the nine months ended September 30, 2016, and 2015, zero and 6,444 PSAs, respectively, were not achieved due to performance against the MSCI REIT Index correlating to less than the maximum achievable during the performance period.

The following table sets forth the number of unvested PSAs and the weighted-average fair value of these awards at the date of grant:

				Weighted-
				Average Fair
	Performance-Based Restricted Stock Awards			Value at Grant
	Minimum	Maximum	Target	Date
Unvested balance, December 31, 2015	10,203	142,963	92,802	$	42.78
Granted	11,796	82,572	47,184		84.78
Forfeited	(7,988)	(55,916)	(31,952)		69.12
Vested	(125)	(1,894)	(1,180)		42.17
Unvested balance, September 30, 2016	13,886	167,725	106,854	$	54.24

As of September 30, 2016, total unearned compensation on PSAs was approximately $3.3 million, and the weighted-average vesting period was 2.2 years. The fair value of each PSA award is estimated on the date of grant using a Monte Carlo simulation. The simulation requires assumptions for expected volatility, risk-free rate of return, and dividend yield.

20

The following table summarizes the assumptions used to value the PSAs granted during the nine months ended September 30, 2016, and 2015.

	Nine Months Ended September 30,
	2016		2015
Expected term (in years)	2.83		2.83
Expected volatility	25.29	%	25.51	%
Expected annual dividend(1)	—		—
Risk-free rate	0.97	%	1.02	%

(1) The fair value of the PSAs assumes reinvestment of dividends.

10. Earnings Per Share

Basic net income per share is calculated by dividing the net income attributable to common shares by the weighted-average number of common shares outstanding during the period. Diluted net income per share adjusts basic net income per share for the effects of potentially dilutive common shares, if the effect is not antidilutive. Potentially dilutive common stock consists of shares issuable under the 2010 Plan. The following is a summary of basic and diluted net income per share (in thousands, except share and per share amounts):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Net income attributable to common shares	$	12,180	$	6,920	$	35,476	$	17,026
Weighted-average common shares outstanding - basic		33,425,762		26,126,332		31,906,000		24,029,106
Effect of potentially dilutive common shares:
Stock options		192,272		238,386		197,166		329,833
Unvested awards		294,121		184,819		258,201		185,673
Weighted-average common shares outstanding - diluted		33,912,155		26,549,537		32,361,367		24,544,612
Net income per share attributable to common shares
Basic	$	0.36	$	0.26	$	1.11	$	0.71
Diluted	$	0.36	$	0.26	$	1.10	$	0.69

In the calculations above, we have excluded weighted-average potentially dilutive securities of 7,757 and 40,565 for the three months ended September 30, 2016, and 2015, respectively, and 113,920 and 157,534 for the nine months ended September 30, 2016, and 2015, respectively, as their effect would have been antidilutive.

11. Estimated Fair Value of Financial Instruments

Authoritative guidance issued by FASB establishes a hierarchy of valuation techniques based on the observability of inputs utilized in measuring assets and liabilities at fair values. This hierarchy establishes market-based or observable inputs as the preferred source of values, followed by valuation models using management assumptions in the absence of market inputs. The three levels of the hierarchy under the authoritative guidance are as follows:

Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the assessment date.

Level 2 — Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

Level 3 — Unobservable inputs for the asset or liability.

Our financial instruments consist of cash and cash equivalents, accounts and other receivables, interest rate swaps, the revolving credit facility, the senior unsecured term loans, senior unsecured notes, interest payable and accounts payable. The carrying values of cash and cash equivalents, accounts and other receivables, interest payable and accounts payable approximate fair values due to the short-term nature of these financial instruments. The interest rate swaps are recorded at fair value.

21

The valuation of our derivatives is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative, which reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves. We have determined that the majority of the inputs used to value our derivatives fall within Level 2 of the fair value hierarchy; however, the credit valuation adjustments associated with our derivatives utilize Level 3 inputs, such as estimates of current credit spreads, to evaluate the likelihood of default by our Operating Partnership and its counterparties. As of September 30, 2016, we have assessed the significance of the impact of the credit valuation adjustments on the overall valuation of our derivative positions and have determined that the credit valuation adjustment is not significant to the overall valuation of our derivative portfolio. As a result we classify our derivative valuation in Level 2 of the fair value hierarchy.

The total principal balance of our revolving credit facility, senior unsecured term loans, and senior unsecured notes was $594.8 million and $392.3 million as of September 30, 2016, and December 31, 2015, respectively, with a fair value that approximated book value based on Level 3 inputs from the fair value hierarchy. Under the discounted cash flow method, the fair values of the revolving credit facility and the senior unsecured term loans are based on our assumptions of market interest rates and terms available incorporating our credit risk for similar loan maturities.

12. Commitments and Contingencies

Our properties require periodic investments of capital for general capital improvements and for tenant-related capital expenditures. We enter into various construction and equipment contracts with third parties for the development of our properties. At September 30, 2016, we had open commitments related to construction contracts of approximately $49.8 million.

On August 11, 2016, we entered into a contract to acquire Sunrise Technology Park, a 21.75-acre light-industrial / flex office park located in Reston, VA, for a purchase price of $65.1 million. Pursuant to the purchase agreement and subject to customary closing conditions, we agreed to purchase the property following the defeasance by the property owner of an existing loan encumbering the property.

Additionally, we have commitments related to telecommunications capacity used to connect data centers located within the same market or geographical area, power usage, and company-wide improvements that are ancillary to revenue generation. At September 30, 2016, we had open commitments related to these contracts of approximately $9.6 million.

We entered into a Memorandum of Understanding with the Virginia Economic Development Partnership Authority (the “Virginia Memorandum of Understanding”) pursuant to which we are afforded the opportunity to benefit from an exemption from sales and use tax for certain qualifying data center related purchases and equipment leases. This exemption also extends to our customers who execute a Landlord-Tenant Participation Agreement under the Virginia Memorandum of Understanding.  The Virginia Memorandum of Understanding establishes thresholds relating to the level of capital investment and qualifying new jobs created within the Commonwealth of Virginia by us and our customers who have agreed to sign participation agreements. In the event those thresholds are not met as of the agreed upon performance date of June 1, 2017, we would be required to repay the sales and use tax benefit we have received, as well as any tax benefit received by our customers who default on their obligation to repay the tax benefit they have received under the exemption program up to a maximum of $7.5 million. We estimate that we may be required to repay between $0.0 million and $4.0 million for sales and use tax benefits we have received under the exemption program, of which none has been accrued in accounts payable and accrued expenses in our condensed consolidated balance sheets as of September 30, 2016, and December 31, 2015, as we believe we will meet the thresholds as of the performance date.

In the ordinary course of business, we are subject to claims and administrative proceedings. Except as described below, we are not presently party to any proceeding, which we believe to be material or which we would expect to have, individually or in the aggregate, a material adverse effect on our business, financial condition, cash flows or results of operations. 

On February 4, 2014, U.S. Colo, LLC (“U.S. Colo”), a current customer, filed a complaint against us in the United States District Court for the Central District of California.  In the complaint, U.S. Colo alleged that it should not have been charged for the use of various interconnection services under the terms of an existing agreement between the parties.

On July 23, 2015, after amendments to the complaint, dismissal of several of U.S. Colo’s claims, and a remand of the case to the Superior Court of the State of California, County of Los Angeles (the “Superior Court”), U.S. Colo filed an

22

amended complaint alleging breach of contract and breach of the covenant of good faith and fair dealing.  The amended complaint seeks $802,564 in damages for charges paid to us for interconnection services; $70,080,000 in damages for alleged losses of revenue and profits; attorney’s fees, interest, and costs of the suit; and declaratory and injunctive relief. 

On February 4, 2016, the Superior Court granted our motion for summary adjudication, finding that U.S. Colo had contractually waived all claims for lost revenue or profits or other consequential damages.

The case was set to start trial on August 29, 2016, but upon unopposed application, the Superior Court vacated the August 29, 2016, trial date, continued the trial date to July 24, 2017, set a final status conference for July 14, 2017, and reset other procedural deadlines in the action.

On July 9, 2015, a purported class action lawsuit was filed in the Superior Court of the State of California, County of Los Angeles, against us, alleging various employment law violations related to overtime, meal and break periods, minimum wage, timely payment of wages, wage statements, payroll records and business expenses. On March 15, 2016, we filed a responsive pleading generally denying the allegations. On July 27, 2016, the parties entered into a Memorandum of Understanding, pursuant to which the parties agreed to settle the lawsuit. The settlement, which remains subject to Superior Court approval, resolves the matter on a class-wide basis, on behalf of all non-exempt employees in California, as well a related class action lawsuit filed on July 22, 2016, alleging similar claims, in exchange for a $600,000 payment to be made by us. We anticipate that a hearing for Superior Court approval of the settlement will occur during the first quarter of 2017. There can be no assurance that the settlement will be finally approved by the Superior Court.

We intend to vigorously defend both of these legal proceedings. While it is not feasible to predict or determine the outcome of these legal proceedings, as of September 30, 2016, we estimate that the ultimate resolution of these litigation matters and other disputes could result in a loss that is reasonably possible between $0.6 million and $3.1 million in the aggregate, of which $2.9 million has been accrued in accounts payable and accrued expenses in our consolidated balance sheet as of September 30, 2016.

23

ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Forward-Looking Statements

This Quarterly Report on Form 10-Q (this “Quarterly Report”), together with other statements and information publicly disseminated by our company, contains certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 (“PSLRA”), namely Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). We intend such forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in the PSLRA and include this statement for purposes of complying with these safe harbor provisions.

In particular, statements pertaining to our capital resources, portfolio performance, business strategies and results of operations contain forward-looking statements. You can identify forward-looking statements by the use of forward-looking terminology such as “believes,”  “expects” “may,” “will,” “should,” “seeks,” “intends,” “plans,” “pro forma” or “anticipates” or the negative of these words and phrases or similar words or phrases that are predictions of or indicate future events or trends and that do not relate solely to historical matters. You can also identify forward-looking statements by discussions of strategy, plans or intentions. Such statements are subject to risks, uncertainties and assumptions and are not guarantees of future performance, which may be affected by known and unknown risks, trends, uncertainties and factors that are beyond our control. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those anticipated, estimated or projected. The following factors, among others, could cause actual results and future events to differ materially from those set forth or contemplated in the forward-looking statements: (i) the geographic concentration of our data centers in certain markets and any adverse developments in local economic conditions or the demand for data center space in these markets; (ii) fluctuations in interest rates and increased operating costs; (iii) difficulties in identifying properties to acquire and completing acquisitions; (iv) the significant competition in our industry and an inability to lease vacant space, renew existing leases or release space as leases expire; (v) lack of sufficient customer demand to realize expected returns on our investments to expand our property portfolio; (vi) decreased revenue from costs and disruptions associated with any failure of our physical infrastructure or services; (vii) our ability to lease available space to existing or new customers; (viii) our failure to obtain necessary outside financing; (ix) our failure to qualify or maintain our status as a REIT; (x) financial market fluctuations; (xi) changes in real estate and zoning laws and increases in real estate taxes; (xii) delays or disruptions in third-party network connectivity; (xiii) service failures or price increases by third party power suppliers; (xiv) inability to renew net leases on the data center properties we lease; and (xv) other factors affecting the real estate or technology industries generally.

While forward-looking statements reflect our good faith beliefs, they are not guarantees of future performance. We disclaim any obligation to publicly update or revise any forward-looking statement to reflect changes in underlying assumptions or factors, of new information, data or methods, future events or other changes, except as required by applicable law. The risks included here are not exhaustive, and additional factors could adversely affect our business and financial performance, including factors and risks included in other sections of this Quarterly Report. Additional information concerning these and other risks and uncertainties is contained in our other periodic filings with the United States Securities and Exchange Commission (“SEC”) pursuant to the Exchange Act. We discussed a number of material risks in Item 1A. “Risk Factors” of our Annual Report on Form 10-K for the year ended December 31, 2015. Those risks continue to be relevant to our performance and financial condition. Given these risks and uncertainties, investors should not place undue reliance on forward-looking statements as a prediction of actual results.

Overview

Unless the context requires otherwise, references in this Quarterly Report to “we,” “our,” “us” and “our company” refer to CoreSite Realty Corporation, a Maryland corporation, together with our consolidated subsidiaries, including CoreSite, L.P., a Delaware limited partnership of which we are the sole general partner and to which we refer in this Quarterly Report as our “Operating Partnership.”

We are engaged in the business of ownership, acquisition, construction and operation of strategically located data centers in eight of the largest and fastest growing data center markets in the United States, including the Northern Virginia (including Washington D.C.), New York and San Francisco Bay areas, Chicago, Los Angeles, Boston, Miami and Denver.

24

We deliver secure, reliable, high-performance data center and interconnection solutions to a growing customer ecosystem across eight key North American markets. We connect, protect and deliver a reliable performance environment and continued operation of mission-critical data and information technology infrastructure for more than 1,000 of the world’s leading enterprises, network operators, cloud providers, and supporting service providers.

Our focus is to bring together a network and cloud community to support the needs of enterprises, and create a diverse customer ecosystem. Our growth strategy includes (i) increasing cash flow from in-place data center space, (ii) capitalizing on embedded expansion opportunities within existing data centers, (iii) selectively pursuing acquisition and development opportunities in existing and new markets, (iv) expanding existing customer relationships, and (v) attracting new customers.

Our Portfolio

As of September 30, 2016, our property portfolio included 18 operating data center facilities, office and light-industrial space and multiple development projects that collectively comprise over 2.9 million net rentable square feet (“NRSF”), of which over 1.9 million NRSF is existing data center space. The 0.6 million NRSF of development projects includes space available for development and construction of new facilities. We expect that this development potential plus any incremental investment into existing or new markets will enable us to accommodate existing and future customer demand and position us to continue to increase our operating cash flows. The following table provides an overview of our property portfolio as of September 30, 2016:

	Data Center Operating NRSF (1)											Development
			Stabilized			Pre-Stabilized (2)			Total			NRSF (3)	Total NRSF
	Annualized			Percent			Percent			Percent			Total
Market/Facilities	Rent ($000)(4)		Total	Occupied(5)		Total	Occupied(5)		Total	Occupied(5)		Total	Portfolio
Los Angeles
One Wilshire campus
LA1*	$	28,310	139,053	91.5	%	—	—	%	139,053	91.5	%	10,352	149,405
LA2		29,405	254,343	89.4		43,345	15.6		297,688	78.6		127,202	424,890
Los Angeles Total		57,715	393,396	90.1		43,345	15.6		436,741	82.7		137,554	574,295
San Francisco Bay
SV1		6,572	85,932	83.9		—	—		85,932	83.9		—	85,932
SV2		8,349	76,676	93.7		—	—		76,676	93.7		—	76,676
Santa Clara campus(6)		37,168	388,589	98.6		—	—		388,589	98.6		230,000	618,589
San Francisco Bay Total		52,089	551,197	95.6		—	—		551,197	95.6		230,000	781,197
Northern Virginia
VA1		27,502	201,719	95.0		—	—		201,719	95.0		—	201,719
VA2		12,050	115,336	100.0		73,111	8.0		188,447	64.3		—	188,447
DC1*		3,276	22,137	87.0		—	—		22,137	87.0		—	22,137
Northern Virginia Total		42,828	339,192	96.2		73,111	8.0		412,303	80.5		—	412,303
Chicago
CH1		18,633	178,407	93.4		—	—		178,407	93.4		—	178,407
Boston
BO1		17,121	166,026	98.7		14,031	54.6		180,057	95.2		73,619	253,676
New York
NY1*		5,015	48,404	71.5		—	—		48,404	71.5		—	48,404
NY2		9,367	68,822	94.9		32,920	44.4		101,742	78.5		134,508	236,250
New York Total		14,382	117,226	85.2		32,920	44.4		150,146	76.3		134,508	284,654
Miami
MI1		1,937	30,176	82.9		—	—		30,176	82.9		13,154	43,330
Denver
DE1*		1,349	5,878	100.0		—	—		5,878	100.0		23,906	29,784
DE2*		438	5,140	98.3		—	—		5,140	98.3		—	5,140
Denver Total		1,787	11,018	99.2		—	—		11,018	99.2		23,906	34,924
Total Data Center	$	206,492	1,786,638	93.7	%	163,407	21.4	%	1,950,045	87.6	%	612,741	2,562,786
Office and Light-Industrial(7)		7,622	354,721	76.8		—	—		354,721	76.8		—	354,721
Total Portfolio	$	214,114	2,141,359	90.9	%	163,407	21.4	%	2,304,766	86.0	%	612,741	2,917,507

*Indicates properties in which we hold a leasehold interest.

(1) Represents NRSF at each operating facility that is currently occupied or readily available for lease as data center space and pre-stabilized data center space. Both occupied and available data center NRSF includes a factor based on management’s estimate to account for a customer’s proportionate share of the required data center support space (such as the mechanical, telecommunications and utility rooms) and building common areas, which may be updated on a periodic basis to reflect the most current build-out of our properties. Operating data center NRSF may require investment of Deferred Expansion Capital (see definition on page 28).

25

(2) Pre-stabilized NRSF represents projects or facilities that recently have been developed and are in the initial lease-up phase. Pre-stabilized projects or facilities become stabilized operating properties at the earlier of achievement of 85% occupancy or 24 months after development completion.

(3) Represents incremental data center capacity currently vacant in existing facilities in our portfolio that requires significant capital investment in order to develop into data center facilities. Includes NRSF under construction for which substantial activities are ongoing to prepare the property for its intended use following development. The NRSF reflects management’s estimate of engineering drawings and required support space and is subject to change based on final demising of space.

(4) Represents the monthly contractual rent under existing commenced customer leases as of September 30, 2016, multiplied by 12. This amount reflects total annualized base rent before any one-time or non-recurring rent abatements and excludes power revenue, interconnection revenue and operating expense reimbursement. On a gross basis, our total portfolio annualized rent was approximately $220.0 million as of September 30, 2016, which reflects the addition of $5.9 million in operating expense reimbursements to contractual net rent under modified gross and triple-net leases. See footnote (6) below for more information regarding annualized rent for the Santa Clara campus.

(5) Includes customer leases that have commenced and are occupied as of September 30, 2016. The percent occupied is determined based on leased square feet as a proportion of total operating NRSF as of September 30, 2016. The percent occupied for stabilized data center space would have been 94.3%, rather than 93.7%, if all leases signed in the current and prior periods had commenced. The percent occupied for our total portfolio, including stabilized data center space, pre-stabilized space and office and light-industrial space, would have been 87.0%, rather than 86.0%, if all leases signed in current and prior periods had commenced.

(6) The annualized rent for the Santa Clara campus includes amounts associated with a restructured lease agreement involving a customer that has vacated its leased space and is paying discounted rent payments that may be applied to new lease arrangements elsewhere in our portfolio on a dollar-for-dollar basis until the original lease terms expire. The $4.2 million payable pursuant to this agreement is scheduled to expire in the second quarter of 2017.

(7) Represents space that is currently occupied or readily available for lease as space other than data center space, which typically is offered for office or light-industrial uses.

26

“Same-Store” statistics are based on space within each data center facility that was leased or available to be leased as of December 31, 2014, excluding space for which development was completed and became available to be leased after September 30, 2016. We track Same-Store space leased or available to be leased at the computer room level within each data center facility. The following table shows the September 30, 2016, Same-Store operating statistics. For comparison purposes, the operating activity totals as of December 31, 2015, and 2014, for this space are provided at the bottom of this table.

	Same-Store Property Portfolio (in NRSF)
			Data Center			Office and Light-Industrial			Total
	Annualized			Percent			Percent			Percent
Market/Facilities	Rent ($000)(1)		Total	Occupied(2)		Total	Occupied(2)		Total	Occupied(2)
Los Angeles
One Wilshire campus
LA1*	$	28,481	139,053	91.5	%	4,373	76.4	%	143,426	91.0	%
LA2		26,252	234,801	89.0		7,029	86.5		241,830	88.9
Los Angeles Total		54,733	373,854	89.9		11,402	82.6		385,256	89.7
San Francisco Bay
SV1		12,101	85,932	83.9		234,238	79.2		320,170	80.5
SV2		8,349	76,676	93.7		—	—		76,676	93.7
Santa Clara campus(3)		33,095	252,009	97.9		712	84.3		252,721	97.8
San Francisco Bay Total		53,545	414,617	94.2		234,950	79.3		649,567	88.8
Northern Virginia
VA1		28,538	201,719	95.0		61,050	86.8		262,769	93.1
DC1*		3,276	22,137	87.0		—	—		22,137	87.0
Northern Virginia Total		31,814	223,856	94.2		61,050	86.8		284,906	92.6
Chicago
CH1		16,224	166,776	93.9		4,946	71.3		171,722	93.3
Boston
BO1		16,071	166,026	98.7		19,495	75.7		185,521	96.3
New York
NY1*		5,028	48,404	71.5		209	100.0		48,613	71.7
NY2		6,079	52,692	93.3		20,735	20.3		73,427	72.7
New York Total		11,107	101,096	82.9		20,944	21.1		122,040	72.3
Miami
MI1		1,960	30,176	82.9		1,934	55.7		32,110	81.2
Denver
DE1*		1,107	4,726	100.0		—	—		4,726	100.0
DE2*		438	5,140	98.3		—	—		5,140	98.3
Denver Total		1,545	9,866	99.1		—	—		9,866	99.1
Total Facilities at September 30, 2016(4)	$	186,999	1,486,267	92.6	%	354,721	76.8	%	1,840,988	89.6	%
Total Facilities at December 31, 2015	$	178,041		89.9	%		71.9	%		86.5	%
Total Facilities at December 31, 2014	$	156,646		81.9	%		75.8	%		80.7	%

*Indicates properties in which we hold a leasehold interest.

(1) Represents the monthly contractual rent under existing commenced customer leases as of each respective period, multiplied by 12. This amount reflects total annualized base rent before any one-time or non-recurring rent abatements and excludes power revenue, interconnection revenue and operating expense reimbursement.

(2) Includes customer leases that have commenced and are occupied as of each respective period. The percent occupied is determined based on leased square feet as a proportion of total operating NRSF.

(3) The annualized rent for the Santa Clara campus includes amounts associated with a restructured lease agreement involving a customer that has vacated its leased space and is paying discounted rent payments that may be applied to new lease arrangements elsewhere in our portfolio on a dollar-for-dollar basis until the original terms expire. The $4.2 million payable pursuant to this agreement is scheduled to expire in the second quarter of 2017.

(4) The percent occupied for data center space, office and light-industrial space, and total space would have been 93.3%, 76.9% and 90.1%, respectively, if all leases signed in the current and prior periods had commenced.

Same-Store annualized rent increased to $187.0 million at September 30, 2016, compared to $178.0 million at December 31, 2015. The increase of $9.0 million in annualized rent is due primarily to the 7.8% increase in data center occupancy at our Los Angeles campus which resulted in an increase of 29,191 occupied NRSF at the campus.

27

Development space is unoccupied space or entitled land that requires significant capital investment in order to develop data center facilities that are ready for use. The following table summarizes the NRSF under construction and NRSF held for development throughout our portfolio, each as of September 30, 2016:

	Development Opportunities (in NRSF)
	Under	Held for
Facilities	Construction(1)	Development(2)	Total
San Francisco Bay
Santa Clara campus(3)	230,000	—	230,000
Los Angeles
One Wilshire campus
LA1	—	10,352	10,352
LA2	4,726	122,476	127,202
Los Angeles Total	4,726	132,828	137,554
Boston
BO1	—	73,619	73,619
New York
NY2	—	134,508	134,508
Miami
MI1	—	13,154	13,154
Denver
DE1	8,276	15,630	23,906
Total Facilities(4)	243,002	369,739	612,741

(1) Represents NRSF for which substantial activities are ongoing to prepare the property for its intended use following development. The NRSF reflects management’s estimate of engineering drawings and required support space and is subject to change based on final demising of space.

(2) Represents estimated incremental data center capacity currently vacant in existing facilities in our portfolio that requires significant capital investment in order to develop into data center facilities.

(3) On October 12, 2016, we completed construction of SV7, a 230,000 NRSF data center, and commenced operating activities of the facility.

(4) In addition to our development opportunities disclosed within this table, we have entitled and unentitled land adjacent to our NY2 and LA2 facilities, in the form of existing parking lots. By utilizing existing parking lots, we believe that we could develop 100,000 NRSF and 200,000 NRSF buildings at NY2 and LA2, respectively, upon receipt of necessary entitlements.

Capital Expenditures

The following table sets forth information regarding capital expenditures during the nine months ended September 30, 2016 (in thousands):

	Nine Months Ended
	September 30, 2016
Data center expansion	$	236,493
Non-recurring investments		8,286
Tenant improvements		4,551
Recurring capital expenditures		4,018
Total capital expenditures	$	253,348

During the nine months ended September 30, 2016, we incurred approximately $253.3 million of capital expenditures, of which approximately $236.5 million related to data center expansion activities, including new data center construction, the development of capacity within existing data centers and other revenue generating investments. As we construct data center capacity, we work to optimize both the amount of the capital we deploy on power and cooling infrastructure and the timing of that capital deployment; as such, we generally construct our power and cooling infrastructure supporting our data center NRSF based on our estimate of customer utilization. This practice can result in our investment at a later time in “Deferred Expansion Capital”. We define Deferred Expansion Capital as our estimate of the incremental capital

28

we may invest in the future to add power or cooling infrastructure to support existing or anticipated future customer utilization of NRSF within our operating data centers.

During the nine months ended September 30, 2016, we completed development of seven computer rooms placed into service at three properties and a 136,580 NRSF powered shell data center at our Santa Clara campus. The following table sets forth capital expenditures spent on data center NRSF placed into service during the nine months ended September 30, 2016, or under construction at September 30, 2016:

			NRSF
	Data Center		Placed into	Under
Property	Expansion		Service	Construction
BO1	$	3,396	14,031	—
LA2		10,264	43,345	4,726
SV6		11,342	136,580	—
SV7		184,671	—	230,000
VA2		10,566	96,274	—
Other		16,254	—	8,276
Total	$	236,493	290,230	243,002

During the nine months ended September 30, 2016, we incurred approximately $8.3 million in non-recurring investments, of which $5.3 million is a result of internal IT software development and the remaining $3.0 million is a result of other non-recurring investments, such as remodel or upgrade projects.

During the nine months ended September 30, 2016, we incurred approximately $4.6 million in tenant improvements, which relates to small tenant improvement projects at various properties.

During the nine months ended September 30, 2016, we incurred approximately $4.0 million of recurring capital expenditures within our portfolio for required equipment upgrades that have a future economic benefit.

Factors that May Influence our Results of Operations

A complete discussion of factors that may influence our results of operations can be found in our Annual Report on Form 10-K for the year ended December 31, 2015, filed with the SEC on February 12, 2016, which is accessible on the SEC’s website at www.sec.gov.

Our ability to re-lease expiring space at rental rates equal to or in excess of current rental rates will impact our results of operations. In addition to approximately 323,000 NRSF of space currently unoccupied in our total portfolio, 197 and 918 data center leases representing approximately 4.2% and 16.6% of the NRSF in our operating data center portfolio with current average annualized rental rates of $167 per NRSF and $151 per NRSF are scheduled to expire during the remainder of 2016 and the year ending December 31, 2017, respectively.

29

The amount of revenue generated by the properties in our portfolio depends on several factors, including our ability to maintain or improve the occupancy rates of currently leased space and to lease currently available space. In addition, the loss of one or more significant customers could have a material adverse effect on our results of operations. Excluding space held for development, as of September 30, 2016, the occupancy rate of data center properties in our portfolio, stabilized and pre-stabilized, was 87.6% of NRSF, compared to 85.4% as of September 30, 2015. During the nine months ended September 30, 2016, new and expansion leases totaling approximately 211,000 NRSF were signed. The following table summarizes our leasing activity during the nine months ended September 30, 2016:

			GAAP		Total
		Number of	Annualized		Leased	GAAP Rental			GAAP Rent
	Three Months Ended	Leases(1)	Rent		NRSF(2)	Rates(3)			Growth(4)
New/expansion leases commenced	September 30, 2016	178	$	7,493	50,455	$	148
	June 30, 2016	152		8,699	157,642		55	(5)
	March 31, 2016	133		7,549	45,965		164
New/expansion leases signed	September 30, 2016	162	$	11,214	59,991	$	187
	June 30, 2016	171		7,656	48,147		159
	March 31, 2016	119		22,478	102,678		219
Renewal leases signed	September 30, 2016	157	$	10,872	76,735	$	142		6.8	%
	June 30, 2016	173		8,512	70,028		122		9.4
	March 31, 2016	171		9,732	56,333		173		9.2

(1) Number of leases represents each agreement with a customer; a lease agreement could include multiple spaces and a customer could have multiple leases.

(2) Total leased NRSF is determined based on contractually leased square feet, including required data center support space (such as the mechanical, telecommunications and utility rooms) and building common areas.

(3) GAAP rental rates represent annual contractual rent per NRSF adjusted for straight-line rents in accordance with GAAP.

(4) GAAP rent growth represents the increase in rental rates on renewed leases commencing during the period, as compared with the previous period’s rental rates for the same space.

(5) During the three months ended June 30, 2016, a 136,580 build-to-suit powered shell lease at our SV6 facility commenced.

Results of Operations

Three Months Ended September 30, 2016, Compared to the Three Months Ended September 30, 2015

The discussion below relates to our financial condition and results of operations for the three months ended September 30, 2016, and 2015. A summary of our operating results for the three months ended September 30, 2016, and 2015, is as follows (in thousands):

	Three Months Ended September 30,
	2016		2015		$ Change		% Change
Operating revenue	$	101,274	$	86,382	$	14,892	17.2	%
Operating expense		78,769		69,631		9,138	13.1
Operating income		22,505		16,751		5,754	34.4
Interest expense		3,222		2,188		1,034	47.3
Net income		19,319		14,530		4,789	33.0

30

Operating Revenues

Operating revenues during the three months ended September 30, 2016, and 2015, were as follows (in thousands):

	Three Months Ended September 30,
	2016		2015		$ Change		% Change
Data center revenue:
Rental revenue	$	54,219	$	47,135	$	7,084	15.0	%
Power revenue		28,844		23,543		5,301	22.5
Interconnection revenue		13,374		11,400		1,974	17.3
Tenant reimbursement and other		2,826		2,357		469	19.9
Total data center revenue		99,263		84,435		14,828	17.6
Office, light-industrial and other revenue		2,011		1,947		64	3.3
Total operating revenues	$	101,274	$	86,382	$	14,892	17.2	%

A majority of the increase in operating revenues was due to a $12.4 million increase in data center rental and power revenue during the three months ended September 30, 2016, compared to the 2015 period. The increase in data center rental and power revenue is due primarily to the commencement of new and expansion leases of 308,000 NRSF at an average rental rate of $107 per NRSF and the renewal of 253,000 NRSF at a rent growth rate of 7.9% during the twelve months ended September 30, 2016. This increase was partially offset by the move out of customer leases totaling 67,000 NRSF at an average rental rate of $163 per NRSF during the twelve months ended September 30, 2016.

In addition, interconnection revenue increased $2.0 million, or 17.3%, during the three months ended September 30, 2016, compared to the 2015 period, primarily as a result of an increase in the volume of cross connects from new and existing customers. During the twelve months ended September 30, 2016, total cross connections grew 12.5%.

Operating Expenses

Operating expenses during the three months ended September 30, 2016, and 2015, were as follows (in thousands):

	Three Months Ended September 30,
	2016		2015		$ Change		% Change
Property operating and maintenance	$	28,283	$	24,203	$	4,080	16.9	%
Real estate taxes and insurance		3,524		3,216		308	9.6
Depreciation and amortization		26,981		24,347		2,634	10.8
Sales and marketing		4,465		3,775		690	18.3
General and administrative		9,432		8,644		788	9.1
Rent		5,967		5,440		527	9.7
Transaction costs		117		6		111	1,850.0
Total operating expenses	$	78,769	$	69,631	$	9,138	13.1	%

Property operating and maintenance expense increased $4.1 million, or 16.9%, primarily as a result of an increase in power expense due to increased customer consumption as a result of the commencement of new and expansion leases during the twelve months ended September 30, 2016, that resulted in a 21.9% increase in occupied data center NRSF from 1,402,009 NRSF as of September 30, 2015, to 1,709,055 NRSF as of September 30, 2016. In addition, payroll and benefits expense increased due to an increase in facilities and operations headcount associated with increased occupied data center NRSF.

Real estate taxes and insurance increased $0.3 million, or 9.6%, during the three months ended September 30, 2016, compared to the 2015 period, primarily as a result of the receipt of 2016 tax assessments being higher than previous amounts at our Virgina campus.

Depreciation and amortization expense increased $2.6 million as a result of an increase in depreciation expense from approximately 290,000 NRSF of new data center capital projects placed into service during the twelve months ended September 30, 2016, with a cost basis of approximately $125.2 million.

31

Interest Expense

Interest expense increased during the three months ended September 30, 2016, compared to 2015, as a result of the increase in overall debt outstanding offset by an increase in capitalized interest due to data center projects under construction as of September 30, 2016. The overall principal amount of our debt outstanding was $594.8 million and $360.3 million as of September 30, 2016, and 2015, respectively. A summary of interest expense for the three months ended September 30, 2016, and 2015, is as follows (in thousands):

	Three Months Ended September 30,
	2016			2015			$ Change		% Change
Interest expense and fees	$	4,432		$	2,392		$	2,040	85.3	%
Amortization of deferred financing costs		370			413			(43)	(10.4)
Capitalized interest		(1,580)			(617)			(963)	(156.1)
Total interest expense	$	3,222		$	2,188		$	1,034	47.3	%
Percent capitalized		32.9	%		22.0	%

Nine Months Ended September 30, 2016, Compared to the Nine Months Ended September 30, 2015

The discussion below relates to our financial condition and results of operations for the nine months ended September 30, 2016, and 2015. A summary of our operating results for the nine months ended September 30, 2016, and 2015, is as follows (in thousands):

	Nine Months Ended September 30,
	2016		2015		$ Change		% Change
Operating revenue	$	289,844	$	242,373	$	47,471	19.6	%
Operating expense		223,160		197,610		25,550	12.9
Operating income		66,684		44,763		21,921	49.0
Interest expense		7,914		5,183		2,731	52.7
Net income		58,760		39,472		19,288	48.9

Operating Revenues

Operating revenues during the nine months ended September 30, 2016, and 2015, were as follows (in thousands):

	Nine Months Ended September 30,
	2016		2015		$ Change		% Change
Data center revenue:
Rental revenue	$	156,954	$	133,282	$	23,672	17.8	%
Power revenue		80,819		64,782		16,037	24.8
Interconnection revenue		39,093		32,210		6,883	21.4
Tenant reimbursement and other		6,982		6,049		933	15.4
Total data center revenue		283,848		236,323		47,525	20.1
Office, light industrial and other revenue		5,996		6,050		(54)	(0.9)
Total operating revenues	$	289,844	$	242,373	$	47,471	19.6	%

A majority of the increase in operating revenues was due to a $39.7 million increase in data center rental and power revenue during the nine months ended September 30, 2016, compared to the 2015 period. The increase in data center rental and power revenue is due primarily to the commencement of new and expansion leases of 308,000 NRSF at an average rental rate of $107 per NRSF and the renewal of 253,000 NRSF at a rent growth rate of 7.9% during the twelve months ended September 30, 2016. This increase is partially offset by the move out of customer leases totaling 67,000 NRSF at an average rental rate of $163 per NRSF during the twelve months ended September 30, 2016.

In addition, interconnection revenue increased $6.9 million, or 21.4%, during the nine months ended September 30, 2016, compared to the 2015 period, primarily as a result of an increase in the volume of cross connects from new and existing customers. During the twelve months ended September 30, 2016, total cross connections grew 12.5%.

32

Operating Expenses

Operating expenses during the nine months ended September 30, 2016, and 2015, were as follows (in thousands):

	Nine Months Ended September 30,
	2016		2015		$ Change		% Change
Property operating and maintenance	$	78,522	$	65,965	$	12,557	19.0	%
Real estate taxes and insurance		9,659		8,421		1,238	14.7
Depreciation and amortization		77,978		71,209		6,769	9.5
Sales and marketing		13,187		11,813		1,374	11.6
General and administrative		26,970		24,461		2,509	10.3
Rent		16,718		15,690		1,028	6.6
Transaction costs		126		51		75	147.1
Total operating expenses	$	223,160	$	197,610	$	25,550	12.9	%

Property operating and maintenance expense increased $12.6 million, or 19.0%, primarily as a result of an increase in power expense due to increased customer consumption as a result of the commencement of new and expansion leases during the twelve months ended September 30, 2016, that resulted in a 21.9% increase in occupied data center NRSF from 1,402,009 NRSF as of September 30, 2015, to 1,709,055 NRSF as of September 30, 2016. In addition, payroll and benefits expense increased due to an increase in facilities and operations headcount associated with increased occupied data center NRSF.

Real estate taxes and insurance increased $1.2 million during the nine months ended September 30, 2016, compared to the 2015 period, primarily as a result of increased tax assessments at various properties.

Depreciation and amortization expense increased $6.8 million as a result of an increase in depreciation expense from approximately 290,000 NRSF of new data center capital projects placed into service during the twelve months ended September 30, 2016, with a cost basis of approximately $125.2 million.

Interest Expense

Interest expense increased during the nine months ended September 30, 2016, compared to 2015, as a result of the increase in overall debt outstanding during the nine months ended September 30, 2016. The overall principal amount of our debt outstanding was $594.8 million and $360.3 million as of September 30, 2016, and 2015, respectively. A summary of interest expense for the nine months ended September 30, 2016, and 2015, is as follows (in thousands):

	Nine Months Ended September 30,
	2016			2015			$ Change		% Change
Interest expense and fees	$	10,491		$	7,083		$	3,408	48.1	%
Amortization of deferred financing costs		964			999			(35)	(3.5)
Capitalized interest		(3,541)			(2,899)			(642)	(22.1)
Total interest expense	$	7,914		$	5,183		$	2,731	52.7	%
Percent capitalized		30.9	%		35.9	%

Liquidity and Capital Resources

Discussion of Cash Flows

Nine Months Ended September 30, 2016, Compared to Nine Months Ended September 30, 2015

Net cash provided by operating activities was $122.9 million for the nine months ended September 30, 2016, compared to $103.4 million for the nine months ended September 30, 2015, an increase of $19.5 million, or 18.8%. Cash provided by operating activities increased primarily due to growth in data center rental, power and interconnection revenue from existing customers and the completion and subsequent leasing of new data center space.

33

Net cash used in investing activities increased by $167.1 million, or 221.7%, to $242.5 million for the nine months ended September 30, 2016, compared to $75.4 million for the nine months ended September 30, 2015. This increase was due primarily to construction spend on our SV6 and SV7 properties at our Santa Clara campus.

Net cash provided by financing activities was $119.1 million for the nine months ended September 30, 2016, compared to $29.2 million used in financing activities for the nine months ended September 30, 2015. The $148.3 million change in financing activities was primarily a result of cash proceeds from the 2021 Term Loan and the 2023 Notes of $100 million and $150 million, respectively, and net cash payments on the revolving credit facility of $47.5 million during the nine months ended September 30, 2016, compared to cash proceeds from the 2020 Term Loan of $150 million and net cash payments on the revolving credit facility of $108.3 million during the nine months ended September 30, 2015. The increase in cash proceeds from debt instruments was partially offset by an increase of $16.1 million in dividends and distributions paid on our common stock and Operating Partnership units during the nine months ended September 30, 2016, as a result of an increase in the quarterly dividend from $0.42 per share or unit paid during the nine months ended September 30, 2015, to $0.53 per share or unit paid during the nine months ended September 30, 2016.

Analysis of Liquidity and Capital Resources

We have an effective shelf registration statement that allows us to offer for sale various unspecified classes of equity and debt securities. As circumstances warrant, we may issue debt and/or equity securities from time to time on an opportunistic basis, dependent upon market conditions and available pricing. We make no assurance that we can issue and sell such securities on acceptable terms or at all.

Our short-term liquidity requirements primarily consist of funds needed for interest expense, operating costs including utilities, site maintenance costs, real estate and personal property taxes, insurance, rental expenses, sales and marketing and general and administrative expenses, certain capital expenditures, including for the development of data center space and future distributions to common and preferred stockholders and holders of our common Operating Partnership units during the next twelve months. As of September 30, 2016, we had $6.3 million of cash and cash equivalents. Subject to our ability to obtain capital upon favorable terms, we estimate our anticipated development activity over the next twelve months will require approximately $220 million to $240 million of capital investment to expand our operating data center portfolio. The capital investment estimate includes approximately $130 million that we anticipate we will invest over the next twelve months to acquire a 21.75 acre light-industrial / flex office park in Reston, VA, and commence data center redevelopment to extend our position as a multi-tenant data center provider in the Northern Virginia market. The table below summarizes our current projects under construction as of September 30, 2016, and the remaining estimated capital required:

				Costs
	Metropolitan	Estimated		Incurred to-		Estimated				Percent
Projects/Facilities	Market	Completion	NRSF	Date		Total		Per NRSF		Leased
TKD(1)
SV7	San Francisco Bay	Q4 2016	230,000	$	208,172	$	211,000	$	917	61.7	%
LA2	Los Angeles	Q4 2016	4,726		392		2,000		423	100.0
DE1(2)	Denver	Q2 2017	8,276		1,980		12,500		1,510	—
Total TKD			243,002	$	210,544	$	225,500			60.3	%
Deferred Expansion Capital
NY2	New York	Q4 2016	—	$	4,581	$	6,100
CH1	Chicago	Q1 2017	—		1,914		10,000
VA2	Northern Virginia	Q1 2017	—		3,913		10,400
TotalDeferredExpansionCapital			—	$	10,408	$	26,500
Total			243,002	$	220,952	$	252,000

(1) Turn-Key Data Center (“TKD”) estimated development costs includes two components: (1) general construction to ready the NRSF as data center space and (2) power, cooling and other infrastructure to provide the designed amount of power capacity for the project. Following development completion, incremental capital, referred to as Deferred Expansion Capital, may be invested to support existing or anticipated future customer utilization of NRSF within our operating data centers.

(2) Includes a portion of the cost of infrastructure to support later phases of the development.

34

We expect to meet our short-term liquidity requirements, including our anticipated development activity over the next twelve months, through net cash provided by operations and by incurring additional indebtedness, including drawing on our revolving credit facility or other debt instruments. In June 2015, our Operating Partnership and certain subsidiary co-borrowers entered into a third amended and restated credit agreement (“the “Credit Agreement”), which provides a total commitment of $600.0 million, including a $350.0 million revolving credit facility and $250.0 million of term loans. During the nine months ended September 30, 2016, we entered into a $100 million senior unsecured term loan under the Credit Agreement, maturing on February 2, 2021, and issued $150 million of senior unsecured notes due June 15, 2023. The proceeds from these two transactions were used to pay down the revolving credit facility and increase our short-term liquidity. The total amount available for borrowing under our revolving credit facility is equal to the lesser of $350.0 million or the availability calculated on our unencumbered asset pool. As of September 30, 2016, $94.8 million was borrowed and outstanding, $4.5 million was outstanding under letters of credit and therefore $250.7 million remained available for us to borrow under our revolving credit facility. Our Credit Agreement contains an accordion feature which allows our Operating Partnership to increase the total commitment by $200.0 million under specified circumstances, including securing capital from new or existing lenders. Our indebtedness maturity schedule is summarized below and as of September 30, 2016, we were in compliance with all of the covenants under our debt arrangements.

Our long-term liquidity requirements primarily consist of the costs to fund Deferred Expansion Capital or additional phases of our current projects under development, future development of other space in our portfolio not currently scheduled, property acquisitions, future distributions to common and preferred stockholders and holders of our common Operating Partnership units, scheduled debt maturities and other capital expenditures. We expect to meet our long-term liquidity requirements through net cash provided by operations, after payment of dividends, and by incurring long-term indebtedness, such as drawing on our revolving credit facility, exercising our senior unsecured term loan accordion features or entering into new debt agreements with our bank group or certain accredited investors. We also may raise capital in the future through the issuance of additional equity or debt securities, subject to prevailing market conditions, and/or through the issuance of common Operating Partnership units. However, there is no assurance that we will be able to successfully raise additional capital on acceptable terms or at all.

Indebtedness

A summary of outstanding indebtedness as of September 30, 2016, and December 31, 2015, is as follows (in thousands):

		Maturity	September 30,		December 31,
	InterestRate	Date	2016		2015
Revolving credit facility	2.08% and 1.98% at September 30, 2016, and December 31, 2015, respectively	June 24, 2019	$	94,750	$	142,250
2019 Senior unsecured term loan	3.23% at September 30, 2016, and December 31, 2015	January 31, 2019		100,000		100,000
2020 Senior unsecured term loan	2.48% and 2.43% at September 30, 2016, and December 31, 2015	June 24, 2020		150,000		150,000
2021 Senior unsecured term loan	2.03% at September 30, 2016	February 2, 2021		100,000		—
2023 Senior unsecured notes	4.19% at September 30, 2016	June 15, 2023		150,000		—
Total principal outstanding				594,750		392,250
Unamortized deferred financing costs				(3,758)		(1,243)
Total debt			$	590,992	$	391,007

As of September 30, 2016, we were in compliance with the covenants under our revolving credit facility, senior unsecured term loans and senior unsecured notes. For additional information with respect to our outstanding indebtedness as of September 30, 2016, and December 31, 2015, as well as the available borrowing capacity under our existing revolving credit facility, debt covenant requirements, and future debt maturities, refer to Item 1. Financial Statements — Note 5 — Debt.

Funds From Operations

We consider funds from operations (“FFO”), a non-GAAP measure, to be a supplemental measure of our performance which should be considered along with, but not as an alternative to, net income and cash provided by operating activities as a measure of operating performance and liquidity. We calculate FFO in accordance with the standards established by the National Association of Real Estate Investment Trusts (“NAREIT”). NAREIT defined FFO represents net income

35

(loss) (computed in accordance with GAAP), excluding gains (or losses) from sales of property and undepreciated land and impairment write-downs of depreciable real estate, plus real estate related depreciation and amortization (excluding amortization of deferred financing costs) and after adjustments for unconsolidated partnerships and joint ventures. FFO attributable to common shares and units represents FFO less preferred stock dividends declared during the period.

Our management uses FFO as a supplemental performance measure because, in excluding real estate related depreciation and amortization and gains and losses from property dispositions, it provides a performance measure that, when compared year over year, captures trends in occupancy rates, rental rates and operating costs.

We offer this measure because we recognize that FFO will be used by investors as a basis to compare our operating performance with that of other REITs. However, because FFO excludes real estate related depreciation and amortization and captures neither the changes in the value of our properties that result from use or market conditions, nor the level of capital expenditures and capitalized leasing commissions necessary to maintain the operating performance of our properties, all of which have real economic effect and could materially impact our financial condition and results from operations, the utility of FFO as a measure of our performance is limited. FFO is a non-GAAP measure and should not be considered a measure of liquidity, an alternative to net income, cash provided by operating activities or any other performance measure determined in accordance with GAAP, nor is it indicative of funds available to fund our cash needs, including our ability to pay dividends or make distributions. In addition, our calculations of FFO are not necessarily comparable to FFO as calculated by other REITs that do not use the same definition or implementation guidelines or interpret the NAREIT standards differently from us. Investors in our securities should not rely on these measures as a substitute for any GAAP measure, including net income. The following table provides a reconciliation of our net income to FFO:

	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands)	2016		2015		2016		2015
Net income	$	19,319	$	14,530	$	58,760	$	39,472
Real estate depreciation and amortization		25,533		22,818		73,782		64,414
Gain on land disposal		—		—		—		(36)
FFO		44,852		37,348		132,542		103,850
Preferred stock dividends		(2,084)		(2,084)		(6,253)		(6,253)
FFO attributable to common shares and units	$	42,768	$	35,264	$	126,289	$	97,597
FFO per common share and OP unit - diluted	$	0.90	$	0.74	$	2.65	$	2.06

Distribution Policy

In order to comply with the REIT requirements of the Internal Revenue Code of 1986, as amended (the “Code”), we are generally required to make annual distributions to our stockholders of at least 90% of our net taxable income. Our common share distribution policy is to distribute a percentage of our cash flow to ensure that we will, at a minimum, meet the distribution requirements of the Code and consider other cash requirements, such as capital improvements, investment activities and other capital needs.

We have made distributions every quarter since our initial public offering. During the three months ended September 30, 2016, we declared a dividend of $0.53 per common share and Operating Partnership Unit as of September 30, 2016. While we plan to continue to make quarterly distributions, no assurances can be made as to the frequency or amounts of any future distributions. The payment of common share distributions is dependent upon our financial condition, operating results and REIT distribution requirements and may be adjusted at the discretion of our Board of Directors during the year.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Market risk refers to the risk of loss from adverse changes in market prices and interest rates. The primary market risk to which we believe we are exposed is interest rate risk. Our future income, cash flows and fair values relevant to financial instruments are dependent upon prevalent market interest rates. Many factors, including governmental monetary and tax policies, domestic and international economic and political considerations and other factors that are beyond our control contribute to interest rate risk.

36

As of September 30, 2016, we had $444.8 million of consolidated principal debt outstanding that bore variable interest based on one month LIBOR. As of September 30, 2016, we have two interest rate swap agreements in place to fix the interest rate on $175.0 million of our one month LIBOR variable rate debt. Our interest rate risk not covered by an interest rate swap agreement is $269.8 million of variable rate debt outstanding as of September 30, 2016. See additional discussion in Item 1. Financial Statements — Note 6 — Derivatives and Hedging Activities.

We monitor our market interest rate risk exposures using a sensitivity analysis. Our sensitivity analysis estimates the exposure to market interest rate risk sensitive instruments assuming a hypothetical 1% change in interest rates on our $269.8 million unhedged variable rate debt. If interest rates were to increase or decrease by 1%, the corresponding increase or decrease, as applicable, in interest expense on our unhedged variable rate debt would increase or decrease, as applicable, future earnings and cash flows by approximately $2.7 million per year.

These analyses do not consider the effect of any change in overall economic activity that could impact interest rates. Further, in the event of an increase in interest rates of significant magnitude, we may take actions to further mitigate our exposure to the change. However, due to the uncertainty of the specific actions that would be taken and their possible effects, these analyses assume no changes in our financial structure.

ITEM 4. CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

We maintain disclosure controls and procedures (as such term is defined in Rule 13a-15(e) and 15d-15(e) under the Exchange Act) that are designed to ensure that information required to be disclosed in our reports under the Exchange Act is processed, recorded, summarized and reported within the time periods specified in the SEC’s rules and regulations and that such information is accumulated and communicated to management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow for timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives, and management is required to apply its judgment in evaluating the cost-benefit relationship of possible controls and procedures.

As of September 30, 2016, we carried out an evaluation, under the supervision and with the participation of management, including our Chief Executive Officer and our Chief Financial Officer, regarding the effectiveness of our disclosure controls and procedures. Based on the foregoing, our Chief Executive Officer and our Chief Financial Officer concluded that our disclosure controls and procedures were effective as of September 30, 2016.

Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting (as such term is defined in Rules 13a-15(f) and 15(d)-15(f) under the Exchange Act) that occurred during the three months ended September 30, 2016, that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

37

PART II - OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

In the ordinary course of our business, we are subject to claims and administrative proceedings. Except as described below we are not presently party to any proceeding which we believe to be material or which we would expect to have, individually or in the aggregate, a material adverse effect on our business, financial condition, cash flows or results of operations.

On February 4, 2014, U.S. Colo, LLC (“U.S. Colo”), a current customer, filed a complaint against us in the United States District Court for the Central District of California. In the complaint, U.S. Colo alleged that it should not have been charged for the use of various CoreSite interconnection services under the terms of an existing agreement between the parties. On July 23, 2015, after amendments to the complaint, dismissal of several of U.S. Colo’s claims, and a remand of the case to the Superior Court of the State of California, County of Los Angeles (the “Superior Court”), U.S. Colo filed an amended complaint alleging breach of contract and breach of the covenant of good faith and fair dealing. The amended complaint seeks $802,564 in damages for charges paid to us for interconnection services; $70,080,000 in damages for alleged losses of revenue and profits; attorney’s fees, interest, and costs of the suit; and declaratory and injunctive relief. On February 4, 2016, the Superior Court granted our motion for summary adjudication, finding that U.S. Colo had contractually waived all claims for lost revenue or profits or other consequential damages. The case was set to start trial on August 29, 2016, but upon unopposed application, the Superior Court vacated the August 29, 2016, trial date, continued the trial date to July 24, 2017, set a final status conference for July 14, 2017, and reset other procedural deadlines in the action.

On July 9, 2015, a purported class action lawsuit was filed in the Superior Court of the State of California, County of Los Angeles, against us, alleging various employment law violations related to overtime, meal and break periods, minimum wage, timely payment of wages, wage statements, payroll records and business expenses. On March 15, 2016, we filed a responsive pleading generally denying the allegations. On July 27, 2016, the parties entered into a Memorandum of Understanding, pursuant to which the parties agreed to settle the lawsuit. The settlement, which remains subject to Superior Court approval, resolves the matter on a class-wide basis, on behalf of all non-exempt employees in California, as well a related class action lawsuit filed on July 22, 2016, alleging similar claims, in exchange for a $600,000 payment to be made by us.  We anticipate that a hearing for Superior Court approval of the settlement will occur during the first quarter of 2017. There can be no assurance that the settlement will be finally approved by the Superior Court.

We intend to vigorously defend both of these legal proceedings.

ITEM 1A. RISK FACTORS

There have been no material changes to the risk factors included in the section entitled “Risk Factors” of our Annual Report on Form 10-K for the year ended December 31, 2015, filed with the SEC on February 12, 2016, which is accessible on the SEC’s website at www.sec.gov.

ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

SALES OF UNREGISTERED EQUITY SECURITIES

None.

REPURCHASES OF EQUITY SECURITIES

None.

ITEM 3. DEFAULTS UPON SENIOR SECURITIES

None.

38

ITEM 4. MINE SAFETY DISCLOSURES

Not applicable.

ITEM 5. OTHER INFORMATION

None.

ITEM 6. EXHIBITS

Exhibit Number	Description
3.1	Articles of Amendment and Restatement of CoreSite Realty Corporation.(1)
3.2	Articles Supplementary of CoreSite Realty Corporation — 7.25% Series A Cumulative Redeemable Preferred Stock.(2)
3.3	Bylaws of CoreSite Realty Corporation.(1)
4.1	Specimen certificate representing the Common Stock of CoreSite Realty Corporation.(3)
10.1	Consulting and Separationg Agreement, dated July 27, 2016, among CoreSite Realty Corporation, CoreSite, L.P., CoreSite L.L.C. and Thomas M. Ray.(4)
10.2	Employment Agreeement, dated July 27, 2016, between CoreSite, L.L.C. and Paul E. Szurek.(4)
31.1	Certification of Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
31.2	Certification of Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
32.1	Certification of Chief Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
32.2	Certification of Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
101.INS	XBRL Instance Document.
101.SCH	XBRL Taxonomy Extension Schema Document.
101.CAL	XBRL Taxonomy Extension Calculation Linkbase Document.
101.LAB	XBRL Taxonomy Extension Labels Linkbase Document.
101.PRE	XBRL Taxonomy Extension Presentation Linkbase Document.
101.DEF	XBRL Taxonomy Extension Definition Linkbase Document.

(1) Incorporated by reference to our Registration Statement (Amendment No. 7) on Form S-11 (Registration No. 333-166810) filed on September 22, 2010.

(2) Incorporated by reference to Exhibit 3.1 to our Current Report on Form 8-K filed on December 18, 2012.

(3) Incorporated by reference to our Post-Effective Amendment to our Registration Statement on Form S-11 (Registration No. 333-166810) filed on September 22, 2010.

(4) Incorporated by reference to our Current Report on Form 8-K filed July 28, 2016.

39

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	CORESITE REALTY CORPORATION
Date: October 28, 2016	By:	/s/ Jeffrey S. Finnin
		Jeffrey S. Finnin
		Chief Financial Officer
		(Principal Financial Officer)

40

Exhibit Index

Exhibit Number	Description
3.1	Articles of Amendment and Restatement of CoreSite Realty Corporation.(1)
3.2	Articles Supplementary of CoreSite Realty Corporation — 7.25% Series A Cumulative Redeemable Preferred Stock.(2)
3.3	Bylaws of CoreSite Realty Corporation.(1)
4.1	Specimen certificate representing the Common Stock of CoreSite Realty Corporation.(3)
10.1	Consulting and Separationg Agreement, dated July 27, 2016, among CoreSite Realty Corporation, CoreSite, L.P., CoreSite L.L.C. and Thomas M. Ray.(4)
10.2	Employment Agreeement, dated July 27, 2016, between CoreSite, L.L.C. and Paul E. Szurek.(4)
31.1	Certification of Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
31.2	Certification of Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
32.1	Certification of Chief Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
32.2	Certification of Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
101.INS	XBRL Instance Document.
101.SCH	XBRL Taxonomy Extension Schema Document.
101.CAL	XBRL Taxonomy Extension Calculation Linkbase Document.
101.LAB	XBRL Taxonomy Extension Labels Linkbase Document.
101.PRE	XBRL Taxonomy Extension Presentation Linkbase Document.
101.DEF	XBRL Taxonomy Extension Definition Linkbase Document.

(1) Incorporated by reference to our Registration Statement (Amendment No. 7) on Form S-11 (Registration No. 333-166810) filed on September 22, 2010.

(2) Incorporated by reference to Exhibit 3.1 to our Current Report on Form 8-K filed on December 18, 2012.

(3) Incorporated by reference to our Post-Effective Amendment to our Registration Statement on Form S-11 (Registration No. 333-166810) filed on September 22, 2010.

(4) Incorporated by reference to our Current Report on Form 8-K filed July 28, 2016.

41

EX-31.1

Exhibit 31.1

Certification of Chief Executive Officer

Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

I, Paul E. Szurek, certify that:

1. I have reviewed this quarterly report on Form 10-Q of CoreSite Realty Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Dated: October 28, 2016

By:	/s/ Paul E. Szurek
	Paul E. Szurek
	Chief Executive Officer
	(Principal Executive Officer)

EX-31.2

Exhibit 31.2

Certification of Chief Financial Officer

Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

I, Jeffrey S. Finnin, certify that:

1. I have reviewed this quarterly report on Form 10-Q of CoreSite Realty Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Dated: October 28, 2016

By:	/s/ Jeffrey S. Finnin
	Jeffrey S. Finnin
	Chief Financial Officer
	(Principal Financial Officer)

EX-32.1

Exhibit 32.1

Certification of Chief Executive Officer Pursuant to 18 U.S.C. Section 1350,

as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

Pursuant to 18 U.S.C. § 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, the undersigned officer of CoreSite Realty Corporation (the “Company”) hereby certifies, to such officer’s knowledge, that:

(i) The accompanying Quarterly Report on Form 10-Q of the Company for the quarter ended September 30, 2016 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(ii) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company for the period covered by the Report.

Dated: October 28, 2016

/s/ Paul E. Szurek

Paul E. Szurek

Chief Executive Officer

EX-32.2

Exhibit 32.2

Certification of Chief Financial Officer Pursuant to 18 U.S.C. Section 1350,

as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

Pursuant to 18 U.S.C. § 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, the undersigned officer of CoreSite Realty Corporation (the “Company”) hereby certifies, to such officer’s knowledge, that:

(i) The accompanying Quarterly Report on Form 10-Q of the Company for the quarter ended September 30, 2016 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(ii) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company for the period covered by the Report.

Dated: October 28, 2016

/s/ Jeffrey S. Finnin

Jeffrey S. Finnin

Chief Financial Officer

XML

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 26, 2016
Document and Entity Information
Entity Registrant Name	CoreSite Realty Corp
Entity Central Index Key	0001490892
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		33,895,155
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3

XML

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Investments in real estate:
Land	$ 82,463	$ 74,819
Buildings and improvements	1,186,712	1,037,127
Total investments in real estate	1,269,175	1,111,946
Less: Accumulated depreciation and amortization	(345,224)	(284,219)
Net investment in operating properties	923,951	827,727
Construction in progress	272,928	183,189
Net investments in real estate	1,196,879	1,010,916
Cash and cash equivalents	6,296	6,854
Accounts and other receivables, net of allowance for doubtful accounts of $97 and $56 as of September 30, 2016, and December 31, 2015, respectively	16,103	12,235
Lease intangibles, net of accumulated amortization of $11,790 and $11,437 as of September 30, 2016, and December 31, 2015, respectively	3,249	4,714
Goodwill	41,191	41,191
Other assets, net	96,274	86,633
Total assets	1,359,992	1,162,543
Liabilities:
Debt, net of unamortized deferred financing costs of $3,758 and $1,243 as of September 30, 2016, and December 31, 2015, respectively	590,992	391,007
Accounts payable and accrued expenses	86,129	75,783
Accrued dividends and distributions	28,630	28,104
Deferred rent payable	7,577	7,934
Acquired below-market lease contracts, net of accumulated amortization of $5,241 and $5,279 as of September 30, 2016, and December 31, 2015, respectively	4,059	4,693
Unearned revenue, prepaid rent and other liabilities	33,444	28,717
Total liabilities	750,831	536,238
Stockholders' equity:
Series A Cumulative Preferred Stock 7.25%, $115,000 liquidation preference ($25.00 per share, $0.01 par value), 4,600,000 shares issued and outstanding as of September 30, 2016, and December 31, 2015	115,000	115,000
Common Stock, par value $0.01, 100,000,000 shares authorized and 33,893,326 and 30,650,703 shares issued and outstanding at September 30, 2016, and December 31, 2015, respectively	334	301
Additional paid-in capital	436,311	390,200
Accumulated other comprehensive loss	(2,141)	(493)
Distributions in excess of net income	(105,756)	(88,891)
Total stockholders' equity	443,748	416,117
Noncontrolling interests	165,413	210,188
Total equity	609,161	626,305
Total liabilities and equity	$ 1,359,992	$ 1,162,543

XML

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
CONDENSED CONSOLIDATED BALANCE SHEETS
Allowance for doubtful accounts (in dollars)	$ 97	$ 56
Accumulated amortization, lease intangibles (in dollars)	11,790	11,437
Unamortized Debt Issuance Expense	3,758	1,243
Accumulated amortization of below-market lease	$ 5,241	$ 5,279
Series A Cumulative Preferred Stock, dividend rate (as a percent)	7.25%	7.25%
Series A Cumulative Preferred Stock, liquidation preference	$ 115,000	$ 115,000
Series A Cumulative Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series A Cumulative Preferred Stock, shares issued	4,600,000	4,600,000
Series A Cumulative Preferred Stock, shares outstanding	4,600,000	4,600,000
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common Stock, shares issued	33,893,326	30,650,703
Common Stock, shares outstanding	33,893,326	30,650,703

XML

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Data center revenue:
Rental revenue	$ 54,219	$ 47,135	$ 156,954	$ 133,282
Power revenue	28,844	23,543	80,819	64,782
Interconnection revenue	13,374	11,400	39,093	32,210
Tenant reimbursement and other	2,826	2,357	6,982	6,049
Office, light-industrial and other revenue	2,011	1,947	5,996	6,050
Total operating revenues	101,274	86,382	289,844	242,373
Operating expenses:
Property operating and maintenance	28,283	24,203	78,522	65,965
Real estate taxes and insurance	3,524	3,216	9,659	8,421
Depreciation and amortization	26,981	24,347	77,978	71,209
Sales and marketing	4,465	3,775	13,187	11,813
General and administrative	9,432	8,644	26,970	24,461
Rent	5,967	5,440	16,718	15,690
Transaction Costs	117	6	126	51
Total operating expenses	78,769	69,631	223,160	197,610
Operating income	22,505	16,751	66,684	44,763
Gain on real estate disposal				36
Interest income	34	1	35	5
Interest expense	(3,222)	(2,188)	(7,914)	(5,183)
Income before income taxes	19,317	14,564	58,805	39,621
Income tax expense	2	(34)	(45)	(149)
Net income	19,319	14,530	58,760	39,472
Net income attributable to noncontrolling interests	5,055	5,526	17,031	16,193
Net income attributable to CoreSite Realty Corporation	14,264	9,004	41,729	23,279
Preferred stock dividends	(2,084)	(2,084)	(6,253)	(6,253)
Net income attributable to common shares	$ 12,180	$ 6,920	$ 35,476	$ 17,026
Net income per share attributable to common shares:
Basic (in dollars per share)	$ 0.36	$ 0.26	$ 1.11	$ 0.71
Diluted (in dollars per share)	$ 0.36	$ 0.26	$ 1.10	$ 0.69
Weighted average common shares outstanding
Basic (in shares)	33,425,762	26,126,332	31,906,000	24,029,106
Diluted (in shares)	33,912,155	26,549,537	32,361,367	24,544,612

XML

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 19,319	$ 14,530	$ 58,760	$ 39,472
Other comprehensive income(loss):
Unrealized gain (loss) on derivative contracts	824	(2,947)	(3,597)	(3,807)
Reclassification of other comprehensive income to interest expense	432	567	1,338	1,371
Comprehensive income	20,575	12,150	56,501	37,036
Comprehensive income attributable to noncontrolling interests	5,423	4,469	16,214	15,016
Comprehensive income attributable to CoreSite Realty Corporation	$ 15,152	$ 7,681	$ 40,287	$ 22,020

XML

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - 9 months ended Sep. 30, 2016 - USD ($) $ in Thousands	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Distributions in Excess of Net Income	Total Stockholders' Equity	Noncontrolling Interests	Total
Balance at Dec. 31, 2015	$ 115,000	$ 301	$ 390,200	$ (493)	$ (88,891)	$ 416,117	$ 210,188	$ 626,305
Balance (in shares) at Dec. 31, 2015		30,650,703
Increase (Decrease) in Stockholders' Equity
Redemption of noncontrolling interests		$ 30	37,550	(206)		37,374	(37,374)
Redemption of noncontrolling interests (in shares)		3,007,000
Issuance of stock awards, net of forfeitures (in shares)		164,014
Exercise of stock options, net of settlements		$ 1	1,242			1,243		1,243
Exercise of stock options, net of settlements (in shares)		71,609
Share-based compensation		$ 2	7,319			7,321		7,321
Dividends declared on preferred stock					(6,253)	(6,253)		(6,253)
Dividends and distributions					(52,341)	(52,341)	(23,615)	(75,956)
Net income					41,729	41,729	17,031	58,760
Other comprehensive loss				(1,442)		(1,442)	(817)	(2,259)
Balance at Sep. 30, 2016	$ 115,000	$ 334	$ 436,311	$ (2,141)	$ (105,756)	$ 443,748	$ 165,413	$ 609,161
Balance (in shares) at Sep. 30, 2016		33,893,326

XML

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 58,760	$ 39,472
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	77,978	71,209
Amortization of above/below market leases	(417)	(387)
Amortization of deferred financing costs	964	999
Gain on real estate disposal		(36)
Share-based compensation	6,874	5,305
Bad debt expense	272	310
Changes in operating assets and liabilities:
Accounts receivable	(4,140)	(4,214)
Deferred rent receivable	(1,906)	(5,423)
Deferred leasing costs	(10,534)	(11,242)
Other assets	(8,499)	(4,661)
Accounts payable and accrued expenses	1,413	4,045
Unearned revenue, prepaid rent and other liabilities	2,480	8,799
Deferred rent payable	(356)	(737)
Net cash provided by operating activities	122,889	103,439
CASH FLOWS FROM INVESTING ACTIVITIES
Tenant improvements	(3,487)	(5,356)
Real estate improvements	(234,963)	(72,443)
Escrow deposits	(4,075)
Proceeds from real estate disposal		2,399
Net cash used in investing activities	(242,525)	(75,400)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from exercise of stock options	1,243	1,171
Proceeds from revolving credit facility	200,250	55,000
Payments on revolving credit facility	(247,750)	(163,250)
Proceeds from unsecured term loan	250,000	150,000
Payments of loan fees and costs	(2,981)	(2,315)
Payments to net settle equity awards		(4,256)
Dividends and distributions	(81,684)	(65,574)
Net cash provided by (used in) financing activities	119,078	(29,224)
Net change in cash and cash equivalents	(558)	(1,185)
Cash and cash equivalents, beginning of period	6,854	10,662
Cash and cash equivalents, end of period	6,296	9,477
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for interest, net of capitalized amounts	5,912	4,501
NON-CASH INVESTING AND FINANCING ACTIVITY
Construction in Progress Expenditures Incurred but Not yet Paid	46,048	18,943
Accrual of dividends and distributions	$ 28,630	$ 22,688

XML

Organization and Description of Business

9 Months Ended

Sep. 30, 2016

Organization and Description of Business

Organization and Description of Business

1. Organization and Description of Business

CoreSite Realty Corporation (the “Company,” “we,”  “us,” or “our”) was organized in the state of Maryland on February 17, 2010, and is a fully-integrated, self-administered, and self-managed real estate investment trust (“REIT”). Through our controlling interest in CoreSite, L.P. (our “Operating Partnership”), we are engaged in the business of owning, acquiring, constructing and operating data centers. As of September 30, 2016, the Company owns a 70.7% common interest in our Operating Partnership and affiliates of The Carlyle Group and others own a 29.3% interest in our Operating Partnership. See additional discussion in Note 8, Noncontrolling Interests — Operating Partnership.

XML

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2016

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Principles of Consolidation and Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared by our management in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and in compliance with the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, these unaudited condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of our management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. The results of operations for the three and nine months ended September 30, 2016, are not necessarily indicative of the expected results for the year ending December 31, 2016. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2015. Intercompany balances and transactions have been eliminated upon consolidation.

In 2016, we adopted ASU 2015-02, Amendments to the Consolidation Analysis. This standard amends certain guidance applicable to the consolidation of various legal entities, including variable interest entities (“VIE”). We evaluated the application of ASU 2015-02 and concluded that no change was required to the accounting for our interest in our Operating Partnership. However, under the new guidance, our Operating Partnership now meets the definition and criteria of a VIE and we are the primary beneficiary of the VIE. Our sole significant asset is the investment in our Operating Partnership, and consequently, substantially all of our assets and liabilities represent those assets and liabilities of our Operating Partnership. Our debt is an obligation of our Operating Partnership where the creditors also have recourse against the credit of the Company. 

Recent Accounting Pronouncements

In August 2016, the Financial Accounting Standards Board (“FASB”) issued guidance codified in Accounting Standards Codification (“ASC”) Topic 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The standard provides guidance on eight specific cash flow classification issues including debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, and separately identifiable cash flows and application of the predominance principle. The standard will be effective for the fiscal year beginning January 1, 2018, and subsequent interim periods. We do not expect the provisions of ASC 2016-15 to have a material impact on our consolidated financial statements.

In March 2016, the Financial Accounting Standards Board (“FASB”) issued guidance codified in Accounting Standards Codification (“ASC”) Topic 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The standard simplifies several aspects related to the accounting for share-based payment transactions, including the accounting for income taxes, statutory tax withholding requirements and classification on the statement of cash flows. The standard will be effective for the fiscal year beginning January 1, 2017 and subsequent interim periods. We do not expect the provisions of ASC 2016-09 to have a material impact on our consolidated financial statements.

In February 2016, the FASB issued guidance codified in ASC Topic 842, Leases, which amends the guidance in former ASC 840, Leases. The standard is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted. The standard requires a modified retrospective transition approach. We are currently evaluating the impact of the provisions of ASC 842 on our lessee and lessor accounting policies and consolidated financial statements.

In May 2014, the FASB issued guidance codified in ASC Topic 606, Revenue Recognition — Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition. The standard is effective for interim and annual reporting periods beginning after December 15, 2017. The standard permits the use of either the retrospective or cumulative effect transition method. We are currently evaluating the impact of the provisions of ASC 606 on our revenue recognition policies as well as the transition method to be used to implement this guidance.

Use of Estimates

The preparation of these unaudited condensed consolidated financial statements in conformity with GAAP requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingencies at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. We evaluate our estimates, including those related to assessing the carrying values of our real estate properties, goodwill, accrued liabilities and performance-based equity compensation plans. We base our estimates on historical experience, current market conditions, and various other assumptions that we believe to be reasonable under the circumstances. Actual results may vary from those estimates and those estimates could vary under different assumptions or conditions.

Adjustments and Reclassifications

Certain immaterial adjustments have been made to the condensed consolidated financial statements for 2015 to conform to the 2016 financial statement presentation.

Investments in Real Estate

Real estate investments are carried at cost less accumulated depreciation and amortization. The cost of real estate includes the purchase price of property and leasehold improvements. Expenditures for maintenance and repairs are expensed as incurred. Significant renovations and betterments that extend the economic useful lives of assets are capitalized. During land development and construction periods, we capitalize construction costs, legal fees, financing costs, real estate taxes and insurance, rental expense and internal costs of personnel performing development, if such costs are incremental and identifiable to a specific development project. Capitalization of costs begins upon commencement of development efforts and ceases when the property is ready for its intended use and held available for occupancy. Interest is capitalized during the period of development based upon applying the weighted-average borrowing rate to the actual development costs expended. Capitalized interest costs were $1.6 million and $0.6 million for the three months ended September 30, 2016, and 2015, respectively, and $3.5 million and $2.9 million for the nine months ended September 30, 2016, and 2015, respectively.

Depreciation and amortization are calculated using the straight-line method over the following useful lives of the assets:

Buildings	27 to 40 years
Building improvements	1 to 10 years
Leasehold improvements	The shorter of the lease term or useful life of the asset

Depreciation expense was $22.3 million and $19.6 million for the three months ended September 30, 2016, and 2015, respectively, and $63.9 million and $56.7 million for the nine months ended September 30, 2016, and 2015, respectively. 

Acquisition of Investment in Real Estate

Purchase accounting is applied to the assets and liabilities related to all real estate investments acquired. The fair value of the real estate acquired is allocated to the acquired tangible assets, consisting primarily of land, building and building improvements, and identified intangible assets and liabilities, consisting of the value of above-market and below-market leases, value of in-place leases and the value of customer relationships.

The fair value of the land and building of an acquired property is determined by valuing the property as if it were vacant, and the “as-if-vacant” fair value is then allocated to land and building based on management's determination of the fair values of these assets. Management determines the as-if-vacant fair value of a property using methods similar to those used by independent appraisers. Factors considered by management in performing these analyses include an estimate of carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases.

The fair value of intangibles related to in-place leases includes the value of lease intangibles for above-market and below-market leases, lease origination costs, and customer relationships, determined on a lease-by-lease basis. Above-market and below-market leases are valued based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) management's estimate of fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining noncancelable term of the lease and, for below-market leases, over a period equal to the initial term plus any below-market fixed rate renewal periods. Lease origination costs include estimates of costs avoided associated with leasing the property, including tenant allowances and improvements and leasing commissions. Customer relationship intangibles relate to the additional revenue opportunities expected to be generated through interconnection services and utility services to be provided to the in-place lease tenants.

The capitalized values for above and below-market lease intangibles, lease origination costs, and customer relationships are amortized over the term of the underlying leases or the expected customer relationship. Amortization related to above-market and below-market leases where the Company is the lessor is recorded as either a reduction of or an increase to rental revenue, amortization related to above-market and below-market leases where the Company is the lessee is recorded as either a reduction of or an increase to rent expense. If a lease is terminated prior to its stated expiration, all unamortized amounts relating to that lease are written off.

The carrying value of intangible assets is reviewed for impairment in connection with its respective asset group whenever events or changes in circumstances indicate that the asset group may not be recoverable. An impairment loss is recognized if the carrying amount of the asset group is not recoverable and its carrying amount exceeds its estimated fair value. No impairment loss related to these intangible assets was recognized for the three or nine months ended September 30, 2016, or 2015.

The excess of the cost of an acquired business over the net of the amounts assigned to assets acquired (including identified intangible assets) and liabilities assumed is recorded as goodwill. As of September 30, 2016, and December 31, 2015, we had approximately $41.2 million of goodwill at each date. The Company’s goodwill has an indeterminate life and is not amortized, but is tested for impairment on an annual basis, or more frequently if events or changes in circumstances indicate that the asset might be impaired. No impairment loss was recognized for the three or nine months ended September 30, 2016, or 2015.

Cash and Cash Equivalents

Cash and cash equivalents include all non-restricted cash held in financial institutions and other non-restricted highly liquid short-term investments with original maturities at acquisition of three months or less.

Deferred Costs

Deferred leasing costs include commissions paid to third parties, including brokers, leasing agents, referral agents, and internal sales commissions paid to employees for successful execution of lease agreements. These commissions and other direct and incremental costs incurred to obtain new customer leases are capitalized and amortized over the lease terms of the related leases using the straight-line method. If a lease terminates prior to the expiration of its initial term, any unamortized deferred costs related to the lease are written off to amortization expense. Deferred leasing costs are included within other assets in the condensed consolidated balance sheets and consisted of the following, net of amortization, as of September 30, 2016, and December 31, 2015 (in thousands):

	September 30,		December 31,
	2016		2015
Internal sales commissions	$	18,678	$	17,558
Third party commissions		13,910		15,866
External legal counsel		740		718
Total	$	33,328	$	34,142

Deferred financing costs include costs incurred in connection with obtaining debt and extending existing debt. These financing costs are capitalized and amortized on a straight-line basis, which approximates the effective-interest method, over the term of the loan and the amortization is included as a component of interest expense. Depending on the type of debt instrument, deferred financing costs are reported either in other assets or as a direct deduction from the carrying amount of the related debt liabilities in our condensed consolidated balance sheets.

Recoverability of Long-Lived Assets

We review our long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Impairment is recognized when estimated expected future cash flows (undiscounted and without interest charges) are less than the carrying amount of the assets. The estimation of expected future net cash flows is inherently uncertain and relies, to a considerable extent, on assumptions regarding current and future economics and market conditions and the availability of capital. If, in future periods, there are changes in the estimates or assumptions incorporated into the impairment review analysis, the changes could result in an adjustment to the carrying amount of the long-lived assets. To the extent that impairment has occurred, the excess of the carrying amount of long-lived assets over its estimated fair value would be recognized as an impairment loss charged to net income. For the three and nine months ended September 30, 2016, and 2015, no impairment of long-lived assets was recognized.

Derivative Instruments and Hedging Activities

We reflect all derivative instruments at fair value as either assets or liabilities on the condensed consolidated balance sheets. For those derivative instruments that are designated and qualify as hedging instruments, we record the effective portion of the gain or loss on the hedging instruments as a component of accumulated other comprehensive income or loss. Any ineffective portion of a derivative's change in fair value is immediately recognized within net income. For derivatives that do not meet the criteria for hedge accounting, changes in fair value are immediately recognized within net income. See additional discussion in Note 6, Derivatives and Hedging Activities.

Internal-Use Software

We recognize internal-use software development costs based on the development stage of the project and nature of the cost. Internal and external costs incurred during the preliminary project stage are expensed as they are incurred. Internal and external costs incurred to develop internal-use software during the application development stage are capitalized. Internal and external training costs and maintenance costs during the post-implementation-operation stage are expensed as incurred. Completed projects are placed into service and amortized over the estimated useful life of the software. No impairment was recognized related to internal-use software in the condensed consolidated statements of operations for the three or nine months ended September 30, 2016, and 2015. 

Revenue Recognition

All customer leases are classified as operating leases and minimum rents are recognized on a straight-line basis over the customer’s lease term. The excess of rents recognized over amounts contractually due pursuant to the underlying leases are included in deferred rent receivable and included in other assets in the condensed consolidated balance sheets.  If a lease terminates prior to its stated expiration, the deferred rent receivable relating to that lease is written off as a reduction of rental revenue.

When arrangements include multiple elements, the revenue associated with separate elements is allocated based on the relative fair values of those elements. The revenue associated with each element is then recognized as earned. Interconnection services and additional space services are considered as separate earnings processes that are provided and completed on a month-to-month basis and revenue is recognized in the period that services are performed. Customer set-up charges and utility installation fees are initially deferred and recognized over the term of the arrangement as revenue.

Tenant reimbursements for real estate taxes, common area maintenance, and other recoverable costs are recognized as revenue in the period that the related expenses are incurred.

Above-market and below-market lease intangibles that were acquired are amortized on a straight-line basis as decreases and increases, respectively, to rental revenue over the remaining noncancelable term of the underlying leases. For both the three months ended September 30, 2016, and 2015, the net effect of amortization of acquired above-market and below-market leases resulted in an increase to rental revenue of $0.1 million. For both the nine months ended September 30, 2016, and 2015, the net effect of amortization of acquired above-market and below market leases resulted in an increase to rental revenue of $0.4 million.

A provision for uncollectible accounts is recorded if a receivable balance relating to contractual rent, rent recorded on a straight-line basis, tenant reimbursements or other billed amounts is considered by management to be uncollectible. At both September 30, 2016, and December 31, 2015, the allowance for doubtful accounts totaled $0.1 million.

Share-Based Compensation

We account for share-based compensation using the fair value method of accounting. The estimated fair value of the stock options granted by us is calculated based on the Black-Scholes option-pricing model. The fair value of restricted share-based and Operating Partnership unit compensation is based on the fair value of our common stock on the date of the grant. The fair value of performance share awards, which have a market condition, is based on a Monte Carlo simulation. The fair value for all share-based compensation is amortized on a straight-line basis over the vesting period.

Asset Retirement and Environmental Remediation Obligations

We record accruals for estimated asset retirement and environmental remediation obligations. The obligations relate primarily to the removal of asbestos during development of properties as well as the estimated equipment removal costs upon termination of a certain lease where we are the lessee. At September 30, 2016, and December 31, 2015, the amounts included in unearned revenue, prepaid rent and other liabilities on the condensed consolidated balance sheets were approximately $1.4 million and $1.7 million, respectively.

Income Taxes

We elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”), commencing with our taxable year ended December 31, 2010. To qualify as a REIT, we are required to distribute at least 90% of our taxable income to our stockholders and meet various other requirements imposed by the Code relating to such matters as operating results, asset holdings, distribution levels and diversity of stock ownership. Provided we qualify for taxation as a REIT, we generally are not subject to corporate level federal income tax on the earnings distributed currently to our stockholders. If we fail to qualify as a REIT in any taxable year, and are unable to avail ourselves of certain savings provisions set forth in the Code, all of our taxable income would be subject to federal income tax at regular corporate rates, including any applicable alternative minimum tax.

To maintain REIT status, we must distribute a minimum of 90% of our taxable income. However, it is our policy and intent, subject to change, to distribute 100% of our taxable income and therefore no provision is required in the accompanying condensed consolidated financial statements for federal income taxes with regards to activities of the REIT and its subsidiary pass-through entities. The allocable share of taxable income is included in the income tax returns of its stockholders. The Company is subject to the statutory requirements of the locations in which it conducts business. State and local income taxes are accrued as deemed required in the best judgment of management based on analysis and interpretation of respective tax laws.

We have elected to treat certain subsidiaries as taxable REIT subsidiaries (“TRS”). Certain activities that we undertake must be conducted by a TRS, such as services for our tenants that could be considered otherwise impermissible for us to perform and holding assets that we cannot hold directly. A TRS is subject to corporate level federal and state income taxes.

Deferred income taxes are recognized in certain taxable entities. Deferred income tax generally is a function of the period's temporary differences (items that are treated differently for tax purposes than for financial reporting purposes), the utilization of tax net operating losses generated in prior years that previously had been recognized as deferred income tax assets and the reversal of any previously recorded deferred income tax liabilities. A valuation allowance for deferred income tax assets is provided if we believe all or some portion of the deferred income tax asset may more likely than not realized. Any increase or decrease in the valuation allowance resulting from a change in circumstances that causes a change in the estimated realizability of the related deferred income tax asset is included in deferred tax expense. As of September 30, 2016, and December 31, 2015, the gross deferred income taxes were not material.

We currently have no liabilities for uncertain income tax positions. The earliest tax year for which we are subject to examination is 2013. 

Concentration of Credit Risks

Our cash and cash equivalents are maintained in various financial institutions, which, at times, may exceed federally insured limits. We have not experienced any losses in such accounts, and management believes that the Company is not exposed to any significant credit risk in this area. We have no off-balance sheet concentrations of credit risk, such as foreign exchange contracts, option contracts, or foreign currency hedging arrangements.

Segment Information

We manage our business as one reportable segment consisting of investments in data centers located in the United States. Although we provide services in several markets, these operations have been aggregated into one reportable segment based on the similar economic characteristics amongst all markets, including the nature of the services provided and the type of customers purchasing these services.

XML

Investment in Real Estate

9 Months Ended

Sep. 30, 2016

Investment in Real Estate

Investment in Real Estate

3. Investment in Real Estate

The following is a summary of the properties owned or leased by market at September 30, 2016 (in thousands):

			Buildings and		Construction in
Market	Land		Improvements		Progress		Total Cost
Boston	$	5,154	$	96,202	$	459	$	101,815
Chicago		5,493		98,549		2,159		106,201
Denver		—		4,878		2,068		6,946
Los Angeles		28,467		232,825		3,439		264,731
Miami		728		10,482		2		11,212
New York		2,388		127,842		38,096		168,326
Northern Virginia		12,442		246,606		7,380		266,428
San Francisco Bay		27,791		369,328		219,325		616,444
Total	$	82,463	$	1,186,712	$	272,928	$	1,542,103

XML

Other Assets

9 Months Ended

Sep. 30, 2016

Other Assets.

Other Assets

4. Other Assets

Our other assets consisted of the following, net of amortization and depreciation, if applicable, as of September 30, 2016, and December 31, 2015 (in thousands):

	September 30,		December 31,
	2016		2015
Deferred leasing costs	$	33,328	$	34,142
Deferred rent receivable		31,215		29,309
Internal-use software		13,010		10,467
Prepaid expenses		6,415		2,689
Corporate furniture, fixtures and equipment		5,556		6,157
Deferred financing costs		1,766		2,251
Other		4,984		1,618
Total	$	96,274	$	86,633

XML

Debt

9 Months Ended

Sep. 30, 2016

Debt

Debt

5. Debt

A summary of outstanding indebtedness as of September 30, 2016, and December 31, 2015, is as follows (in thousands):

		Maturity	September 30,		December 31,
	Interest Rate	Date	2016		2015
Revolving credit facility	2.08% and 1.98% at September 30, 2016, and December 31, 2015, respectively	June 24, 2019	$	94,750	$	142,250
2019 Senior unsecured term loan(1)	3.23% at September 30, 2016, and December 31, 2015	January 31, 2019		100,000		100,000
2020 Senior unsecured term loan(2)	2.48% and 2.43% at September 30, 2016, and December 31, 2015	June 24, 2020		150,000		150,000
2021 Senior unsecured term loan	2.03% at September 30, 2016	February 2, 2021		100,000		—
2023 Senior unsecured notes	4.19% at September 30, 2016	June 15, 2023		150,000		—
Total principal outstanding				594,750		392,250
Unamortized deferred financing costs				(3,758)		(1,243)
Total debt			$	590,992	$	391,007

(1) Our Operating Partnership entered into a swap agreement with respect to the 2019 Term Loan (as defined below) to swap the variable interest rate associated with $100 million, or 100%, of the 2019 Term Loan to a fixed rate of approximately 3.23% per annum at our current leverage ratio. See Note 6 – Derivatives and Hedging Activities.

(2) Our Operating Partnership entered into a swap agreement with respect to the 2020 Term Loan (as defined below) to swap the variable interest rate associated with $75 million, or 50%, of the principal amount of the 2020 Term Loan to a fixed rate of approximately 2.93% per annum at our current leverage ratio. The interest rate on the remaining $75 million of the 2020 Term Loan is based on LIBOR plus the applicable spread. The effective interest rate as of September 30, 2016, is 2.48%. See Note 6 – Derivatives and Hedging Activities.

Revolving Credit Facility

On June 24, 2015, our Operating Partnership and certain subsidiary co-borrowers entered into a third amended and restated credit agreement (as amended, the “Credit Agreement”) with a group of lenders for which KeyBank National Association acts as the administrative agent. The Credit Agreement amended our Operating Partnership’s second amended and restated unsecured revolving credit facility, dated January 3, 2013 (as amended, the “Prior Facility”). The Credit Agreement maturity date is June 24, 2019, with a one-time extension option, which, if exercised, would extend the maturity date to June 24, 2020. The exercise of the extension option is subject to the payment of an extension fee equal to 10 basis points of the total commitment under the Credit Agreement at initial maturity and certain other customary conditions. The Credit Agreement increased the commitment of $405 million from the Prior Facility to $500 million, providing for a $350 million revolving credit facility and a $150 million unsecured term loan scheduled to mature on June 24, 2020. See “2020 Senior Unsecured Term Loan” below for a discussion of the $150 million term loan. The Credit Agreement contains an accordion feature, which allows our Operating Partnership to increase the total commitment from $500 million to $700 million, under specified circumstances, including securing capital from new or existing lenders.

On February 2, 2016, we partially exercised the Credit Agreement accordion feature and entered into a $100 million senior unsecured term loan, which increased our current commitment under the Credit Agreement from $500 million to $600 million. In addition, the accordion feature increased by $100 million, which allows our Operating Partnership to increase the total commitment from $600 million to $800 million under specified circumstances, including securing capital from new or existing lenders. See “2021 Unsecured Term Loan” below for a discussion of the $100 million senior unsecured term loan.

Borrowings under the revolving credit facility bear interest at a variable rate per annum equal to either (i) LIBOR plus 155 basis points to 225 basis points, or (ii) a base rate plus 55 basis points to 125 basis points, each depending on our Operating Partnership’s leverage ratio. At September 30, 2016, our Operating Partnership’s leverage ratio was 20.7% and the interest rate was LIBOR plus 155 basis points.

The total amount available for borrowing under the revolving credit facility, which is part of the Credit Agreement, is equal to the lesser of $350.0 million or the availability calculated based on our unencumbered asset pool. As of September 30, 2016, the borrowing capacity was $350.0 million. As of September 30, 2016, $94.8 million was borrowed and outstanding, $4.5 million was outstanding under letters of credit and therefore $250.8 million remained available for us to borrow under the revolving credit facility.

Our ability to borrow under the Credit Agreement is subject to ongoing compliance with a number of financial covenants and other customary restrictive covenants, including, among others:

· a maximum leverage ratio (defined as total consolidated indebtedness to total gross asset value) of 60%, which, as of September 30, 2016, was 20.7%;

· a maximum secured debt ratio (defined as total consolidated secured debt to total gross asset value) of 40%,  which, as of September 30, 2016, was 0%;

· a minimum fixed charge coverage ratio (defined as adjusted consolidated earnings before interest, taxes, depreciation and amortization to consolidated fixed charges) of 1.7 to 1.0, which, as of September 30, 2016, was 8.1 to 1.0; and

· a maximum unhedged variable rate debt ratio (defined as unhedged variable rate indebtedness to gross asset value) of 30%, which, as of September 30, 2016, our unhedged variable rate debt ratio was 9.3%.

As of September 30, 2016, we were in compliance with all of the covenants under the Credit Agreement.

2019 Senior Unsecured Term Loan

On January 31, 2014, our Operating Partnership and certain subsidiaries entered into a $100 million senior unsecured term loan (as amended, the “2019 Term Loan”). The 2019 Term Loan has a five-year term and contains an accordion feature, which allows our Operating Partnership to increase the total commitments by $100 million, to $200 million, under specified circumstances, including securing capital from new or existing lenders. The 2019 Term Loan ranks pari passu with the 2020 Term Loan, the 2021 Term Loan, the 2023 Notes and the Credit Agreement and contains the same financial covenants and other customary restrictive covenants. As of September 30, 2016, we were in compliance with all of the covenants under the 2019 Term Loan.

The borrowings under the 2019 Term Loan bear interest at a variable rate per annum equal to either (i) LIBOR plus 175 basis points to 265 basis points, or (ii) a base rate plus 75 basis points to 165 basis points, each depending on our Operating Partnership's leverage ratio. At September 30, 2016, our Operating Partnership’s leverage ratio was 20.7% and the interest rate was LIBOR plus 175 basis points. 

2020 Senior Unsecured Term Loan

On June 24, 2015, in connection with, and pursuant to the terms of, the Credit Agreement, our Operating Partnership and certain subsidiaries entered into a $150 million senior unsecured term loan (the “2020 Term Loan”). The 2020 Term Loan has a five-year term maturing on June 24, 2020. The 2020 Term Loan ranks pari passu with the 2019 Term Loan, the 2021 Term Loan, the 2023 Notes and the Credit Agreement and contains the same financial covenants and other customary restrictive covenants. As of September 30, 2016, we were in compliance with all of the covenants under the 2020 Term Loan.

The borrowings under the 2020 Term Loan bear interest at a variable rate per annum equal to either (i) LIBOR plus 150 basis points to 220 basis points, or (ii) a base rate plus 50 basis points to 120 basis points, each depending on our Operating Partnership's leverage ratio. At September 30, 2016, our Operating Partnership’s leverage ratio was 20.7% and the interest rate was LIBOR plus 150 basis points. 

2021 Senior Unsecured Term Loan

On February 2, 2016, pursuant to the terms of the Credit Agreement, we partially exercised the accordion feature and entered into a $100 million senior unsecured term loan (the “2021 Term Loan”). The 2021 Term Loan has a five-year term maturing on February 2, 2021. The 2021 Term Loan ranks pari passu with the 2019 Term Loan, the 2020 Term Loan, the 2023 Notes and the Credit Agreement and contains the same financial covenants and other customary restrictive covenants. As of September 30, 2016, we were in compliance with all of the covenants under the 2021 Term Loan.

The borrowings under the 2021 Term Loan bear interest at a variable rate per annum equal to either (i) LIBOR plus 150 basis points to 220 basis points, or (ii) a base rate plus 50 basis points to 120 basis points, each depending on our Operating Partnership’s leverage ratio. At September 30, 2016, our Operating Partnership’s leverage ratio was 20.7% and the interest rate was LIBOR plus 150 basis points.

2023 Senior Unsecured Notes

On June 15, 2016, our Operating Partnership issued an aggregate principal amount of $150 million, 4.19% senior unsecured notes due June 15, 2023 (the “2023 Notes”) in a private placement to certain accredited investors. The terms of the 2023 Notes are governed by a note purchase agreement, dated June 15, 2016 (the “Note Purchase Agreement”), by and among our Operating Partnership, the Company and the purchasers named therein.

Interest is payable semiannually, on the 15th day of June and December in each year, commencing on December 15, 2016. The 2023 Notes are senior unsecured obligations of our Operating Partnership and are jointly and severally guaranteed by the Company and each of our Operating Partnership’s subsidiaries that guarantees indebtedness under our Operating Partnership’s Credit Agreement (the “Subsidiary Guarantors”).

Our Operating Partnership may prepay all or a portion of the 2023 Notes upon notice to the holders for 100% of the principal amount so prepaid plus a make-whole premium as set forth in the Note Purchase Agreement. Upon the occurrence of certain change of control events, holders of the 2023 Notes will have the right to require our Operating Partnership to purchase 100% of such holder’s 2023 Notes in cash at a purchase price equal to 100% of the principal amount thereof plus accrued and unpaid interest, if any, to the date of repurchase.

The 2023 Notes rank pari passu with the 2019 Term Loan, the 2020 Term Loan, the 2021 Term Loan and the Credit Agreement. The Note Purchase Agreement contains the same financial covenants as the Credit Agreement, as described above. In addition, certain additional financial covenants in the Credit Agreement were automatically incorporated into the Note Purchase Agreement, and, subject to certain conditions, these additional financial covenants will be deleted, removed, amended or otherwise modified to be more or less restrictive if the analogous covenant in the Credit Agreement is so deleted, removed, amended or otherwise modified. The aforementioned covenants are subject to a number of exceptions and qualifications set forth in the Note Purchase Agreement. As of September 30, 2016, we were in compliance with all of the covenants under the Note Purchase Agreement. 

Debt Maturities

The following table summarizes the amount of our outstanding debt as of September 30, 2016, based on when such debt currently becomes due (in thousands):

Year Ending December 31,
Remainder of 2016	$	—
2017		—
2018		—
2019		194,750
2020		150,000
Thereafter		250,000
Total principal outstanding		594,750
Unamortized deferred financing costs		(3,758)
Total debt, net	$	590,992

XML

Derivatives and Hedging Activities

9 Months Ended

Sep. 30, 2016

Derivatives and Hedging Activities

Derivatives and Hedging Activities

6. Derivatives and Hedging Activities

On April 9, 2015, we entered into a $75 million forward starting five-year interest rate swap agreement, effective May 5, 2015, to protect against adverse fluctuation in interest rates. The swap reduces our exposure to variability in cash flows relating to interest payments on $75 million of one-month LIBOR variable rate debt and effectively fixes the interest rate at approximately 2.93% per annum. Also, on February 3, 2014, we entered into a five-year interest rate swap agreement that effectively fixes the interest rate on $100 million of outstanding debt at approximately 3.23% per annum. Both interest rate swap agreements were designated for hedge accounting.

Risk Management Objective of Using Derivatives

We are exposed to certain risks arising from both our business operations and economic conditions. We principally manage our exposures to a wide variety of business and operational risks through management of our core business activities. We manage economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of our debt funding and the use of derivative financial instruments. Specifically, we enter into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known or uncertain cash amounts, the value of which are determined by interest rates. Our derivative financial instruments are used to manage differences in the amount, timing, and duration of our known or expected cash receipts and our known or expected cash payments principally related to our investments and borrowings.

Cash Flow Hedges of Interest Rate Risk

Our objectives in using interest rate derivatives are to reduce variability in interest expense and to manage our exposure to adverse interest rate movements. To accomplish this objective, we primarily use interest rate swaps as part of our interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount.

The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income or loss on the condensed consolidated balance sheets and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The amounts recorded in other comprehensive income related to the unrealized loss or gain on derivative contracts were a gain of $0.8 million and a loss of $2.9 million for the three months ended September 30, 2016, and 2015, respectively, and a loss of $3.6 million and $3.8 million for the nine months ended September 30, 2016, and 2015, respectively. The amounts reclassified from other comprehensive income to interest expense on the condensed consolidated statements of operations were $0.4 million and $0.6 million for the three months ended September 30, 2016, and 2015, respectively, and $1.3 million and $1.4 million for the nine months ended September 30, 2016, and 2015, respectively. The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings. During the three and nine months ended September 30, 2016, and 2015, we did not record any amount in earnings related to derivatives as there was no hedge ineffectiveness.

Amounts reported in accumulated other comprehensive loss related to derivatives will be reclassified to interest expense as interest payments are made on our variable-rate debt. During the subsequent twelve months, beginning October 1, 2016, we estimate that $1.7 million will be reclassified as an increase to interest expense.

Derivatives are recorded at fair value in our condensed consolidated balance sheets in other assets or unearned revenue, prepaid rent and other liabilities, as applicable. We do not net our derivative position by counterparty for purposes of balance sheet presentation and disclosure. We had $3.0 million and $0.8 million in derivative liabilities recognized in unearned revenue, prepaid rent and other liabilities in our condensed consolidated balance sheets as of September 30, 2016, and December 31, 2015, respectively.

XML

Stockholders' Equity

9 Months Ended

Sep. 30, 2016

Stockholders' Equity

Stockholders' Equity

7. Stockholders’ Equity

We declared the following dividends per share on our Series A cumulative preferred stock and common stock during the nine months ended September 30, 2016:

Declaration Date	Record Date	Payment Date	Preferred Stock			Common Stock
March 3, 2016	March 31, 2016	April 15, 2016	$	0.4531	(1)	$	0.53
May 20, 2016	June 30, 2016	July 15, 2016		0.4531	(2)		0.53
September 2, 2016	September 30, 2016	October 17, 2016		0.4531	(3)		0.53
			$	1.3593		$	1.59

(1) Dividend covers the period from January 15, 2016, to April 14, 2016.

(2) Dividend covers the period from April 15, 2016, to July 14, 2016.

(3) Dividend covers the period from July 15, 2016, to October 14, 2016.

XML

Noncontrolling Interests - Operating Partnership

9 Months Ended

Sep. 30, 2016

Noncontrolling Interests - Operating Partnership

Noncontrolling Interests - Operating Partnership

8. Noncontrolling Interests — Operating Partnership

Noncontrolling interests represent the limited partnership interests in our Operating Partnership held by individuals and entities other than CoreSite Realty Corporation. The current holders of common Operating Partnership units are eligible to have the common Operating Partnership units redeemed for cash or common stock on a one-for-one basis, at our option.

In connection with the issuance of our 7.25% Series A cumulative redeemable preferred stock on December 12, 2012, our Operating Partnership issued 4,600,000 7.25% Series A cumulative redeemable preferred Operating Partnership units to us. Preferred Operating Partnership units rank senior to the common Operating Partnership units held by both us and noncontrolling interests.

The following table shows the ownership interests in our Operating Partnership as of September 30, 2016, and December 31, 2015:

	September 30, 2016			December 31, 2015
	Number of Units	Percentage of Total		Number of Units	Percentage of Total
CoreSite Realty Corporation	33,371,340	70.7	%	30,136,556	64.1	%
Noncontrolling interests	13,851,347	29.3		16,858,347	35.9
Total	47,222,687	100.0	%	46,994,903	100.0	%

For each share of common stock issued by us, our Operating Partnership issues to us an equivalent common Operating Partnership unit. During the nine months ended September 30, 2016, we issued 227,784 shares of common stock related to employee compensation arrangements and therefore an equivalent number of common Operating Partnership units were issued to us by our Operating Partnership.

Holders of common Operating Partnership units of record as of September 30, 2016, received quarterly distributions of $0.53 per unit, payable in correlation with declared dividends on common stock.

During the nine months ended September 30, 2016, 3,007,000 common Operating Partnership units held by The Carlyle Group and other third parties were redeemed for shares of our common stock in connection with the sale of 3,007,000 shares of our common stock. This redemption was recorded as a $37.4 million reduction to noncontrolling interests in our Operating Partnership and an increase to total stockholder’s equity in the condensed consolidated balance sheets.

The redemption value of the noncontrolling interests at September 30, 2016, was $1.0 billion based on the closing price of the Company’s common stock of $74.04 on that date.

XML

Equity Incentive Plan

9 Months Ended

Sep. 30, 2016

Equity Incentive Plan

Equity Incentive Plan

9. Equity Incentive Plan

Our Board of Directors adopted and, with the approval of our stockholders, amended the 2010 Equity Incentive Plan (as amended, the “2010 Plan”). The 2010 Plan is administered by the Compensation Committee of the Board of Directors. Awards issuable under the 2010 Plan include common stock, stock options, restricted stock, stock appreciation rights, dividend equivalents, Operating Partnership units and other incentive awards. We have reserved a total of 6,000,000 shares of our common stock for issuance pursuant to the 2010 Plan, which may be adjusted for changes in our capitalization and certain corporate transactions. To the extent that an award expires, terminates or lapses, or an award is settled in cash without the delivery of shares of common stock to the participant, then any unvested shares subject to the award will be available for future grant or sale under the 2010 Plan. Shares of restricted stock which are forfeited or repurchased by us pursuant to the 2010 Plan may again be awarded under the 2010 Plan. The payment of dividend equivalents in cash in conjunction with any outstanding awards will not be counted against the shares available for issuance under the 2010 Plan.

As of September 30, 2016, 3,109,969 shares of our common stock were available for issuance pursuant to the 2010 Plan.

Stock Options

Stock option awards are granted with an exercise price equal to the closing market price of the Company’s common stock on the date of grant. The fair value of each option granted under the 2010 Plan is estimated on the date of grant using the Black-Scholes option-pricing model. The fair values are amortized on a straight-line basis over the vesting periods.

The following table sets forth stock option activity under the 2010 Plan for the nine months ended September 30, 2016:

	Number of
	Shares	Weighted-
	Subject to	Average
	Option	Exercise Price
Options outstanding, December 31, 2015	340,210	$	21.77
Granted	—		—
Exercised	(71,609)		17.35
Forfeited	—		—
Expired	—		—
Options outstanding, September 30, 2016	268,601	$	22.95

The following table sets forth the number of shares subject to options that are unvested as of September 30, 2016, and the fair value of these options at the grant date:

	Number of	Weighted-
	Shares	Average Fair
	Subject to	Value at Grant
	Option	Date
Unvested balance, December 31, 2015	105,267	$	9.13
Granted	—		—
Forfeited	—		—
Vested	(88,944)		8.97
Unvested balance, September 30, 2016	16,323	$	9.99

As of September 30, 2016, total unearned compensation on options was approximately $0.1 million, and the weighted-average vesting period was 0.4 years.

Restricted Awards and Units

Restricted stock awards and restricted stock units, or RSUs, are granted with a fair value equal to the closing market price of the Company’s common stock on the date of grant. The principal difference between restricted stock awards and RSUs is that RSUs are not shares of our common stock and do not have any of the rights or privileges thereof, including voting rights. On the applicable vesting date, the holder of an RSU becomes entitled to a share of common stock. The restricted stock awards and RSUs are amortized on a straight-line basis to expense over the vesting period. The following table sets forth the number of unvested restricted stock awards and RSUs and the weighted-average fair value of these awards at the date of grant:

		Weighted-
	Restricted	Average Fair
	Awards and	Value at Grant
	Units	Date
Unvested balance, December 31, 2015	377,612	$	38.51
Granted	179,511		66.69
Forfeited	(35,046)		53.86
Vested	(196,708)		36.62
Unvested balance, September 30, 2016	325,369	$	53.55

As of September 30, 2016, total unearned compensation on restricted awards was approximately $13.9 million, and the weighted-average vesting period was 2.6 years.

Performance Stock Awards

We grant long-term incentives to members of management in the form of performance-based restricted stock awards (“PSAs”) under the 2010 Plan. The number of PSAs earned is based on our achievement of relative total shareholder return (“TSR”) measured versus the MSCI US REIT Index over a three-year performance period and ranges between 0% and 150% of a target number of shares for PSAs granted in 2014 and between 25% and 175% of the target for PSAs granted in 2015 and 2016. The PSAs are granted at the maximum percentage of target and are retired annually to the extent we do not achieve maximum relative TSR versus the MSCI US REIT Index. The PSAs are earned upon TSR achievement measured both annually and over the full three-year performance period. The PSAs have a service condition and will be released at the end of the three-year performance period, to the extent earned, provided that the holder continues to be employed by the Company at the end of the three-year performance period. Holders of the PSAs are entitled to dividends on the PSAs, which will be accrued and paid in cash at the end of the three-year performance period. During the nine months ended September 30, 2016, and 2015, zero and 6,444 PSAs, respectively, were not achieved due to performance against the MSCI REIT Index correlating to less than the maximum achievable during the performance period.

The following table sets forth the number of unvested PSAs and the weighted-average fair value of these awards at the date of grant:

				Weighted-
				Average Fair
	Performance-Based Restricted Stock Awards			Value at Grant
	Minimum	Maximum	Target	Date
Unvested balance, December 31, 2015	10,203	142,963	92,802	$	42.78
Granted	11,796	82,572	47,184		84.78
Forfeited	(7,988)	(55,916)	(31,952)		69.12
Vested	(125)	(1,894)	(1,180)		42.17
Unvested balance, September 30, 2016	13,886	167,725	106,854	$	54.24

As of September 30, 2016, total unearned compensation on PSAs was approximately $3.3 million, and the weighted-average vesting period was 2.2 years. The fair value of each PSA award is estimated on the date of grant using a Monte Carlo simulation. The simulation requires assumptions for expected volatility, risk-free rate of return, and dividend yield. The following table summarizes the assumptions used to value the PSAs granted during the nine months ended September 30, 2016, and 2015.

	Nine Months Ended September 30,
	2016		2015
Expected term (in years)	2.83		2.83
Expected volatility	25.29	%	25.51	%
Expected annual dividend(1)	—		—
Risk-free rate	0.97	%	1.02	%

(1) The fair value of the PSAs assumes reinvestment of dividends.

XML

Earnings Per Share

9 Months Ended

Sep. 30, 2016

Earnings Per Share

Earnings Per Share

10. Earnings Per Share

Basic net income per share is calculated by dividing the net income attributable to common shares by the weighted-average number of common shares outstanding during the period. Diluted net income per share adjusts basic net income per share for the effects of potentially dilutive common shares, if the effect is not antidilutive. Potentially dilutive common stock consists of shares issuable under the 2010 Plan. The following is a summary of basic and diluted net income per share (in thousands, except share and per share amounts):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Net income attributable to common shares	$	12,180	$	6,920	$	35,476	$	17,026
Weighted-average common shares outstanding - basic		33,425,762		26,126,332		31,906,000		24,029,106
Effect of potentially dilutive common shares:
Stock options		192,272		238,386		197,166		329,833
Unvested awards		294,121		184,819		258,201		185,673
Weighted-average common shares outstanding - diluted		33,912,155		26,549,537		32,361,367		24,544,612
Net income per share attributable to common shares
Basic	$	0.36	$	0.26	$	1.11	$	0.71
Diluted	$	0.36	$	0.26	$	1.10	$	0.69

In the calculations above, we have excluded weighted-average potentially dilutive securities of 7,757 and 40,565 for the three months ended September 30, 2016, and 2015, respectively, and 113,920 and 157,534 for the nine months ended September 30, 2016, and 2015, respectively, as their effect would have been antidilutive.

XML

Estimated Fair Value of Financial Instruments

9 Months Ended

Sep. 30, 2016

Estimated Fair Value of Financial Instruments

Estimated Fair Value of Financial Instruments

11. Estimated Fair Value of Financial Instruments

Authoritative guidance issued by FASB establishes a hierarchy of valuation techniques based on the observability of inputs utilized in measuring assets and liabilities at fair values. This hierarchy establishes market-based or observable inputs as the preferred source of values, followed by valuation models using management assumptions in the absence of market inputs. The three levels of the hierarchy under the authoritative guidance are as follows:

Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the assessment date.

Level 2 — Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

Level 3 — Unobservable inputs for the asset or liability.

Our financial instruments consist of cash and cash equivalents, accounts and other receivables, interest rate swaps, the revolving credit facility, the senior unsecured term loans, senior unsecured notes, interest payable and accounts payable. The carrying values of cash and cash equivalents, accounts and other receivables, interest payable and accounts payable approximate fair values due to the short-term nature of these financial instruments. The interest rate swaps are recorded at fair value.

The valuation of our derivatives is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative, which reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves. We have determined that the majority of the inputs used to value our derivatives fall within Level 2 of the fair value hierarchy; however, the credit valuation adjustments associated with our derivatives utilize Level 3 inputs, such as estimates of current credit spreads, to evaluate the likelihood of default by our Operating Partnership and its counterparties. As of September 30, 2016, we have assessed the significance of the impact of the credit valuation adjustments on the overall valuation of our derivative positions and have determined that the credit valuation adjustment is not significant to the overall valuation of our derivative portfolio. As a result we classify our derivative valuation in Level 2 of the fair value hierarchy.

The total principal balance of our revolving credit facility, senior unsecured term loans, and senior unsecured notes was $594.8 million and $392.3 million as of September 30, 2016, and December 31, 2015, respectively, with a fair value that approximated book value based on Level 3 inputs from the fair value hierarchy. Under the discounted cash flow method, the fair values of the revolving credit facility and the senior unsecured term loans are based on our assumptions of market interest rates and terms available incorporating our credit risk for similar loan maturities.

XML

Commitments and Contingencies

9 Months Ended

Sep. 30, 2016

Commitments and Contingencies.

Commitments and Contingencies

12. Commitments and Contingencies

Our properties require periodic investments of capital for general capital improvements and for tenant-related capital expenditures. We enter into various construction and equipment contracts with third parties for the development of our properties. At September 30, 2016, we had open commitments related to construction contracts of approximately $49.8 million.

On August 11, 2016, we entered into a contract to acquire Sunrise Technology Park, a 21.75-acre light-industrial / flex office park located in Reston, VA, for a purchase price of $65.1 million. Pursuant to the purchase agreement and subject to customary closing conditions, we agreed to purchase the property following the defeasance by the property owner of an existing loan encumbering the property.

Additionally, we have commitments related to telecommunications capacity used to connect data centers located within the same market or geographical area, power usage, and company-wide improvements that are ancillary to revenue generation. At September 30, 2016, we had open commitments related to these contracts of approximately $9.6 million.

We entered into a Memorandum of Understanding with the Virginia Economic Development Partnership Authority (the “Virginia Memorandum of Understanding”) pursuant to which we are afforded the opportunity to benefit from an exemption from sales and use tax for certain qualifying data center related purchases and equipment leases. This exemption also extends to our customers who execute a Landlord-Tenant Participation Agreement under the Virginia Memorandum of Understanding.  The Virginia Memorandum of Understanding establishes thresholds relating to the level of capital investment and qualifying new jobs created within the Commonwealth of Virginia by us and our customers who have agreed to sign participation agreements. In the event those thresholds are not met as of the agreed upon performance date of June 1, 2017, we would be required to repay the sales and use tax benefit we have received, as well as any tax benefit received by our customers who default on their obligation to repay the tax benefit they have received under the exemption program up to a maximum of $7.5 million. We estimate that we may be required to repay between $0.0 million and $4.0 million for sales and use tax benefits we have received under the exemption program, of which none has been accrued in accounts payable and accrued expenses in our condensed consolidated balance sheets as of September 30, 2016, and December 31, 2015, as we believe we will meet the thresholds as of the performance date.

In the ordinary course of business, we are subject to claims and administrative proceedings. Except as described below, we are not presently party to any proceeding, which we believe to be material or which we would expect to have, individually or in the aggregate, a material adverse effect on our business, financial condition, cash flows or results of operations. 

On February 4, 2014, U.S. Colo, LLC (“U.S. Colo”), a current customer, filed a complaint against us in the United States District Court for the Central District of California.  In the complaint, U.S. Colo alleged that it should not have been charged for the use of various interconnection services under the terms of an existing agreement between the parties.

On July 23, 2015, after amendments to the complaint, dismissal of several of U.S. Colo’s claims, and a remand of the case to the Superior Court of the State of California, County of Los Angeles (the “Superior Court”), U.S. Colo filed an amended complaint alleging breach of contract and breach of the covenant of good faith and fair dealing.  The amended complaint seeks $802,564 in damages for charges paid to us for interconnection services; $70,080,000 in damages for alleged losses of revenue and profits; attorney’s fees, interest, and costs of the suit; and declaratory and injunctive relief. 

On February 4, 2016, the Superior Court granted our motion for summary adjudication, finding that U.S. Colo had contractually waived all claims for lost revenue or profits or other consequential damages.

The case was set to start trial on August 29, 2016, but upon unopposed application, the Superior Court vacated the August 29, 2016, trial date, continued the trial date to July 24, 2017, set a final status conference for July 14, 2017, and reset other procedural deadlines in the action.

On July 9, 2015, a purported class action lawsuit was filed in the Superior Court of the State of California, County of Los Angeles, against us, alleging various employment law violations related to overtime, meal and break periods, minimum wage, timely payment of wages, wage statements, payroll records and business expenses. On March 15, 2016, we filed a responsive pleading generally denying the allegations. On July 27, 2016, the parties entered into a Memorandum of Understanding, pursuant to which the parties agreed to settle the lawsuit. The settlement, which remains subject to Superior Court approval, resolves the matter on a class-wide basis, on behalf of all non-exempt employees in California, as well a related class action lawsuit filed on July 22, 2016, alleging similar claims, in exchange for a $600,000 payment to be made by us. We anticipate that a hearing for Superior Court approval of the settlement will occur during the first quarter of 2017. There can be no assurance that the settlement will be finally approved by the Superior Court.

We intend to vigorously defend both of these legal proceedings. While it is not feasible to predict or determine the outcome of these legal proceedings, as of September 30, 2016, we estimate that the ultimate resolution of these litigation matters and other disputes could result in a loss that is reasonably possible between $0.6 million and $3.1 million in the aggregate, of which $2.9 million has been accrued in accounts payable and accrued expenses in our consolidated balance sheet as of September 30, 2016.

XML

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2016

Summary of Significant Accounting Policies

Principles of Consolidation and Basis of Presentation

Principles of Consolidation and Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared by our management in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and in compliance with the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, these unaudited condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of our management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. The results of operations for the three and nine months ended September 30, 2016, are not necessarily indicative of the expected results for the year ending December 31, 2016. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2015. Intercompany balances and transactions have been eliminated upon consolidation.

In 2016, we adopted ASU 2015-02, Amendments to the Consolidation Analysis. This standard amends certain guidance applicable to the consolidation of various legal entities, including variable interest entities (“VIE”). We evaluated the application of ASU 2015-02 and concluded that no change was required to the accounting for our interest in our Operating Partnership. However, under the new guidance, our Operating Partnership now meets the definition and criteria of a VIE and we are the primary beneficiary of the VIE. Our sole significant asset is the investment in our Operating Partnership, and consequently, substantially all of our assets and liabilities represent those assets and liabilities of our Operating Partnership. Our debt is an obligation of our Operating Partnership where the creditors also have recourse against the credit of the Company.

Recent Accounting Pronouncements

Recent Accounting Pronouncements

In August 2016, the Financial Accounting Standards Board (“FASB”) issued guidance codified in Accounting Standards Codification (“ASC”) Topic 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The standard provides guidance on eight specific cash flow classification issues including debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, and separately identifiable cash flows and application of the predominance principle. The standard will be effective for the fiscal year beginning January 1, 2018, and subsequent interim periods. We do not expect the provisions of ASC 2016-15 to have a material impact on our consolidated financial statements.

In March 2016, the Financial Accounting Standards Board (“FASB”) issued guidance codified in Accounting Standards Codification (“ASC”) Topic 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The standard simplifies several aspects related to the accounting for share-based payment transactions, including the accounting for income taxes, statutory tax withholding requirements and classification on the statement of cash flows. The standard will be effective for the fiscal year beginning January 1, 2017 and subsequent interim periods. We do not expect the provisions of ASC 2016-09 to have a material impact on our consolidated financial statements.

In February 2016, the FASB issued guidance codified in ASC Topic 842, Leases, which amends the guidance in former ASC 840, Leases. The standard is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted. The standard requires a modified retrospective transition approach. We are currently evaluating the impact of the provisions of ASC 842 on our lessee and lessor accounting policies and consolidated financial statements.

In May 2014, the FASB issued guidance codified in ASC Topic 606, Revenue Recognition — Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition. The standard is effective for interim and annual reporting periods beginning after December 15, 2017. The standard permits the use of either the retrospective or cumulative effect transition method. We are currently evaluating the impact of the provisions of ASC 606 on our revenue recognition policies as well as the transition method to be used to implement this guidance.

Use of Estimates

Use of Estimates

The preparation of these unaudited condensed consolidated financial statements in conformity with GAAP requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingencies at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. We evaluate our estimates, including those related to assessing the carrying values of our real estate properties, goodwill, accrued liabilities and performance-based equity compensation plans. We base our estimates on historical experience, current market conditions, and various other assumptions that we believe to be reasonable under the circumstances. Actual results may vary from those estimates and those estimates could vary under different assumptions or conditions.

Adjustments and Reclassifications

Adjustments and Reclassifications

Certain immaterial adjustments have been made to the condensed consolidated financial statements for 2015 to conform to the 2016 financial statement presentation.

Investments in Real Estate

Investments in Real Estate

Real estate investments are carried at cost less accumulated depreciation and amortization. The cost of real estate includes the purchase price of property and leasehold improvements. Expenditures for maintenance and repairs are expensed as incurred. Significant renovations and betterments that extend the economic useful lives of assets are capitalized. During land development and construction periods, we capitalize construction costs, legal fees, financing costs, real estate taxes and insurance, rental expense and internal costs of personnel performing development, if such costs are incremental and identifiable to a specific development project. Capitalization of costs begins upon commencement of development efforts and ceases when the property is ready for its intended use and held available for occupancy. Interest is capitalized during the period of development based upon applying the weighted-average borrowing rate to the actual development costs expended. Capitalized interest costs were $1.6 million and $0.6 million for the three months ended September 30, 2016, and 2015, respectively, and $3.5 million and $2.9 million for the nine months ended September 30, 2016, and 2015, respectively.

Depreciation and amortization are calculated using the straight-line method over the following useful lives of the assets:

Buildings	27 to 40 years
Building improvements	1 to 10 years
Leasehold improvements	The shorter of the lease term or useful life of the asset

Depreciation expense was $22.3 million and $19.6 million for the three months ended September 30, 2016, and 2015, respectively, and $63.9 million and $56.7 million for the nine months ended September 30, 2016, and 2015, respectively.

Acquisition of Investment in Real Estate

Acquisition of Investment in Real Estate

Purchase accounting is applied to the assets and liabilities related to all real estate investments acquired. The fair value of the real estate acquired is allocated to the acquired tangible assets, consisting primarily of land, building and building improvements, and identified intangible assets and liabilities, consisting of the value of above-market and below-market leases, value of in-place leases and the value of customer relationships.

The fair value of the land and building of an acquired property is determined by valuing the property as if it were vacant, and the “as-if-vacant” fair value is then allocated to land and building based on management's determination of the fair values of these assets. Management determines the as-if-vacant fair value of a property using methods similar to those used by independent appraisers. Factors considered by management in performing these analyses include an estimate of carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases.

The fair value of intangibles related to in-place leases includes the value of lease intangibles for above-market and below-market leases, lease origination costs, and customer relationships, determined on a lease-by-lease basis. Above-market and below-market leases are valued based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) management's estimate of fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining noncancelable term of the lease and, for below-market leases, over a period equal to the initial term plus any below-market fixed rate renewal periods. Lease origination costs include estimates of costs avoided associated with leasing the property, including tenant allowances and improvements and leasing commissions. Customer relationship intangibles relate to the additional revenue opportunities expected to be generated through interconnection services and utility services to be provided to the in-place lease tenants.

The capitalized values for above and below-market lease intangibles, lease origination costs, and customer relationships are amortized over the term of the underlying leases or the expected customer relationship. Amortization related to above-market and below-market leases where the Company is the lessor is recorded as either a reduction of or an increase to rental revenue, amortization related to above-market and below-market leases where the Company is the lessee is recorded as either a reduction of or an increase to rent expense. If a lease is terminated prior to its stated expiration, all unamortized amounts relating to that lease are written off.

The carrying value of intangible assets is reviewed for impairment in connection with its respective asset group whenever events or changes in circumstances indicate that the asset group may not be recoverable. An impairment loss is recognized if the carrying amount of the asset group is not recoverable and its carrying amount exceeds its estimated fair value. No impairment loss related to these intangible assets was recognized for the three or nine months ended September 30, 2016, or 2015.

The excess of the cost of an acquired business over the net of the amounts assigned to assets acquired (including identified intangible assets) and liabilities assumed is recorded as goodwill. As of September 30, 2016, and December 31, 2015, we had approximately $41.2 million of goodwill at each date. The Company’s goodwill has an indeterminate life and is not amortized, but is tested for impairment on an annual basis, or more frequently if events or changes in circumstances indicate that the asset might be impaired. No impairment loss was recognized for the three or nine months ended September 30, 2016, or 2015.

Cash and Cash Equivalents

Cash and Cash Equivalents

Cash and cash equivalents include all non-restricted cash held in financial institutions and other non-restricted highly liquid short-term investments with original maturities at acquisition of three months or less.

Deferred Costs

Deferred Costs

Deferred leasing costs include commissions paid to third parties, including brokers, leasing agents, referral agents, and internal sales commissions paid to employees for successful execution of lease agreements. These commissions and other direct and incremental costs incurred to obtain new customer leases are capitalized and amortized over the lease terms of the related leases using the straight-line method. If a lease terminates prior to the expiration of its initial term, any unamortized deferred costs related to the lease are written off to amortization expense. Deferred leasing costs are included within other assets in the condensed consolidated balance sheets and consisted of the following, net of amortization, as of September 30, 2016, and December 31, 2015 (in thousands):

	September 30,		December 31,
	2016		2015
Internal sales commissions	$	18,678	$	17,558
Third party commissions		13,910		15,866
External legal counsel		740		718
Total	$	33,328	$	34,142

Deferred financing costs include costs incurred in connection with obtaining debt and extending existing debt. These financing costs are capitalized and amortized on a straight-line basis, which approximates the effective-interest method, over the term of the loan and the amortization is included as a component of interest expense. Depending on the type of debt instrument, deferred financing costs are reported either in other assets or as a direct deduction from the carrying amount of the related debt liabilities in our condensed consolidated balance sheets.

Recoverability of Long-Lived Assets

Recoverability of Long-Lived Assets

We review our long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Impairment is recognized when estimated expected future cash flows (undiscounted and without interest charges) are less than the carrying amount of the assets. The estimation of expected future net cash flows is inherently uncertain and relies, to a considerable extent, on assumptions regarding current and future economics and market conditions and the availability of capital. If, in future periods, there are changes in the estimates or assumptions incorporated into the impairment review analysis, the changes could result in an adjustment to the carrying amount of the long-lived assets. To the extent that impairment has occurred, the excess of the carrying amount of long-lived assets over its estimated fair value would be recognized as an impairment loss charged to net income. For the three and nine months ended September 30, 2016, and 2015, no impairment of long-lived assets was recognized.

Derivative Instruments and Hedging Activities

Derivative Instruments and Hedging Activities

We reflect all derivative instruments at fair value as either assets or liabilities on the condensed consolidated balance sheets. For those derivative instruments that are designated and qualify as hedging instruments, we record the effective portion of the gain or loss on the hedging instruments as a component of accumulated other comprehensive income or loss. Any ineffective portion of a derivative's change in fair value is immediately recognized within net income. For derivatives that do not meet the criteria for hedge accounting, changes in fair value are immediately recognized within net income. See additional discussion in Note 6, Derivatives and Hedging Activities.

Internal-Use Software

Internal-Use Software

We recognize internal-use software development costs based on the development stage of the project and nature of the cost. Internal and external costs incurred during the preliminary project stage are expensed as they are incurred. Internal and external costs incurred to develop internal-use software during the application development stage are capitalized. Internal and external training costs and maintenance costs during the post-implementation-operation stage are expensed as incurred. Completed projects are placed into service and amortized over the estimated useful life of the software. No impairment was recognized related to internal-use software in the condensed consolidated statements of operations for the three or nine months ended September 30, 2016, and 2015.

Revenue Recognition

Revenue Recognition

All customer leases are classified as operating leases and minimum rents are recognized on a straight-line basis over the customer’s lease term. The excess of rents recognized over amounts contractually due pursuant to the underlying leases are included in deferred rent receivable and included in other assets in the condensed consolidated balance sheets.  If a lease terminates prior to its stated expiration, the deferred rent receivable relating to that lease is written off as a reduction of rental revenue.

When arrangements include multiple elements, the revenue associated with separate elements is allocated based on the relative fair values of those elements. The revenue associated with each element is then recognized as earned. Interconnection services and additional space services are considered as separate earnings processes that are provided and completed on a month-to-month basis and revenue is recognized in the period that services are performed. Customer set-up charges and utility installation fees are initially deferred and recognized over the term of the arrangement as revenue.

Tenant reimbursements for real estate taxes, common area maintenance, and other recoverable costs are recognized as revenue in the period that the related expenses are incurred.

Above-market and below-market lease intangibles that were acquired are amortized on a straight-line basis as decreases and increases, respectively, to rental revenue over the remaining noncancelable term of the underlying leases. For both the three months ended September 30, 2016, and 2015, the net effect of amortization of acquired above-market and below-market leases resulted in an increase to rental revenue of $0.1 million. For both the nine months ended September 30, 2016, and 2015, the net effect of amortization of acquired above-market and below market leases resulted in an increase to rental revenue of $0.4 million.

A provision for uncollectible accounts is recorded if a receivable balance relating to contractual rent, rent recorded on a straight-line basis, tenant reimbursements or other billed amounts is considered by management to be uncollectible. At both September 30, 2016, and December 31, 2015, the allowance for doubtful accounts totaled $0.1 million.

Share-Based Compensation

Share-Based Compensation

We account for share-based compensation using the fair value method of accounting. The estimated fair value of the stock options granted by us is calculated based on the Black-Scholes option-pricing model. The fair value of restricted share-based and Operating Partnership unit compensation is based on the fair value of our common stock on the date of the grant. The fair value of performance share awards, which have a market condition, is based on a Monte Carlo simulation. The fair value for all share-based compensation is amortized on a straight-line basis over the vesting period.

Asset Retirement and Environmental Remediation Obligations

Asset Retirement and Environmental Remediation Obligations

We record accruals for estimated asset retirement and environmental remediation obligations. The obligations relate primarily to the removal of asbestos during development of properties as well as the estimated equipment removal costs upon termination of a certain lease where we are the lessee. At September 30, 2016, and December 31, 2015, the amounts included in unearned revenue, prepaid rent and other liabilities on the condensed consolidated balance sheets were approximately $1.4 million and $1.7 million, respectively.

Income Taxes

Income Taxes

We elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”), commencing with our taxable year ended December 31, 2010. To qualify as a REIT, we are required to distribute at least 90% of our taxable income to our stockholders and meet various other requirements imposed by the Code relating to such matters as operating results, asset holdings, distribution levels and diversity of stock ownership. Provided we qualify for taxation as a REIT, we generally are not subject to corporate level federal income tax on the earnings distributed currently to our stockholders. If we fail to qualify as a REIT in any taxable year, and are unable to avail ourselves of certain savings provisions set forth in the Code, all of our taxable income would be subject to federal income tax at regular corporate rates, including any applicable alternative minimum tax.

To maintain REIT status, we must distribute a minimum of 90% of our taxable income. However, it is our policy and intent, subject to change, to distribute 100% of our taxable income and therefore no provision is required in the accompanying condensed consolidated financial statements for federal income taxes with regards to activities of the REIT and its subsidiary pass-through entities. The allocable share of taxable income is included in the income tax returns of its stockholders. The Company is subject to the statutory requirements of the locations in which it conducts business. State and local income taxes are accrued as deemed required in the best judgment of management based on analysis and interpretation of respective tax laws.

We have elected to treat certain subsidiaries as taxable REIT subsidiaries (“TRS”). Certain activities that we undertake must be conducted by a TRS, such as services for our tenants that could be considered otherwise impermissible for us to perform and holding assets that we cannot hold directly. A TRS is subject to corporate level federal and state income taxes.

Deferred income taxes are recognized in certain taxable entities. Deferred income tax generally is a function of the period's temporary differences (items that are treated differently for tax purposes than for financial reporting purposes), the utilization of tax net operating losses generated in prior years that previously had been recognized as deferred income tax assets and the reversal of any previously recorded deferred income tax liabilities. A valuation allowance for deferred income tax assets is provided if we believe all or some portion of the deferred income tax asset may more likely than not realized. Any increase or decrease in the valuation allowance resulting from a change in circumstances that causes a change in the estimated realizability of the related deferred income tax asset is included in deferred tax expense. As of September 30, 2016, and December 31, 2015, the gross deferred income taxes were not material.

We currently have no liabilities for uncertain income tax positions. The earliest tax year for which we are subject to examination is 2013.

Concentration of Credit Risks

Concentration of Credit Risks

Our cash and cash equivalents are maintained in various financial institutions, which, at times, may exceed federally insured limits. We have not experienced any losses in such accounts, and management believes that the Company is not exposed to any significant credit risk in this area. We have no off-balance sheet concentrations of credit risk, such as foreign exchange contracts, option contracts, or foreign currency hedging arrangements.

Segment Information

Segment Information

We manage our business as one reportable segment consisting of investments in data centers located in the United States. Although we provide services in several markets, these operations have been aggregated into one reportable segment based on the similar economic characteristics amongst all markets, including the nature of the services provided and the type of customers purchasing these services.

XML

Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2016

Summary of Significant Accounting Policies

Schedule of useful lives of real estate investment assets

Buildings	27 to 40 years
Building improvements	1 to 10 years
Leasehold improvements	The shorter of the lease term or useful life of the asset

Schedule of deferred leasing costs, net of amortization

Deferred leasing costs are included within other assets in the condensed consolidated balance sheets and consisted of the following, net of amortization, as of September 30, 2016, and December 31, 2015 (in thousands):

	September 30,		December 31,
	2016		2015
Internal sales commissions	$	18,678	$	17,558
Third party commissions		13,910		15,866
External legal counsel		740		718
Total	$	33,328	$	34,142

XML

Investment in Real Estate (Tables)

9 Months Ended

Sep. 30, 2016

Investment in Real Estate

Summary of properties owned or leased

The following is a summary of the properties owned or leased by market at September 30, 2016 (in thousands):

			Buildings and		Construction in
Market	Land		Improvements		Progress		Total Cost
Boston	$	5,154	$	96,202	$	459	$	101,815
Chicago		5,493		98,549		2,159		106,201
Denver		—		4,878		2,068		6,946
Los Angeles		28,467		232,825		3,439		264,731
Miami		728		10,482		2		11,212
New York		2,388		127,842		38,096		168,326
Northern Virginia		12,442		246,606		7,380		266,428
San Francisco Bay		27,791		369,328		219,325		616,444
Total	$	82,463	$	1,186,712	$	272,928	$	1,542,103

XML

Other Assets (Tables)

9 Months Ended

Sep. 30, 2016

Other Assets.

Schedule of other assets

Our other assets consisted of the following, net of amortization and depreciation, if applicable, as of September 30, 2016, and December 31, 2015 (in thousands):

	September 30,		December 31,
	2016		2015
Deferred leasing costs	$	33,328	$	34,142
Deferred rent receivable		31,215		29,309
Internal-use software		13,010		10,467
Prepaid expenses		6,415		2,689
Corporate furniture, fixtures and equipment		5,556		6,157
Deferred financing costs		1,766		2,251
Other		4,984		1,618
Total	$	96,274	$	86,633

XML

Debt (Tables)

9 Months Ended

Sep. 30, 2016

Debt

Summary of outstanding indebtedness

A summary of outstanding indebtedness as of September 30, 2016, and December 31, 2015, is as follows (in thousands):

		Maturity	September 30,		December 31,
	Interest Rate	Date	2016		2015
Revolving credit facility	2.08% and 1.98% at September 30, 2016, and December 31, 2015, respectively	June 24, 2019	$	94,750	$	142,250
2019 Senior unsecured term loan(1)	3.23% at September 30, 2016, and December 31, 2015	January 31, 2019		100,000		100,000
2020 Senior unsecured term loan(2)	2.48% and 2.43% at September 30, 2016, and December 31, 2015	June 24, 2020		150,000		150,000
2021 Senior unsecured term loan	2.03% at September 30, 2016	February 2, 2021		100,000		—
2023 Senior unsecured notes	4.19% at September 30, 2016	June 15, 2023		150,000		—
Total principal outstanding				594,750		392,250
Unamortized deferred financing costs				(3,758)		(1,243)
Total debt			$	590,992	$	391,007

(1) Our Operating Partnership entered into a swap agreement with respect to the 2019 Term Loan (as defined below) to swap the variable interest rate associated with $100 million, or 100%, of the 2019 Term Loan to a fixed rate of approximately 3.23% per annum at our current leverage ratio. See Note 6 – Derivatives and Hedging Activities.

Our Operating Partnership entered into a swap agreement with respect to the 2020 Term Loan (as defined below) to swap the variable interest rate associated with $75 million, or 50%, of the principal amount of the 2020 Term Loan to a fixed rate of approximately 2.93% per annum at our current leverage ratio. The interest rate on the remaining $75 million of the 2020 Term Loan is based on LIBOR plus the applicable spread. The effective interest rate as of September 30, 2016, is 2.48%. See Note 6 – Derivatives and Hedging Activities.

Summary of amount of the entity's outstanding debt when such debt currently become due

The following table summarizes the amount of our outstanding debt as of September 30, 2016, based on when such debt currently becomes due (in thousands):

Year Ending December 31,
Remainder of 2016	$	—
2017		—
2018		—
2019		194,750
2020		150,000
Thereafter		250,000
Total principal outstanding		594,750
Unamortized deferred financing costs		(3,758)
Total debt, net	$	590,992

XML

Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2016

Stockholders' Equity

Schedule of dividends paid per share on Series A Cumulative Preferred Stock and common shares

Declaration Date	Record Date	Payment Date	Preferred Stock			Common Stock
March 3, 2016	March 31, 2016	April 15, 2016	$	0.4531	(1)	$	0.53
May 20, 2016	June 30, 2016	July 15, 2016		0.4531	(2)		0.53
September 2, 2016	September 30, 2016	October 17, 2016		0.4531	(3)		0.53
			$	1.3593		$	1.59

(1) Dividend covers the period from January 15, 2016, to April 14, 2016.

(2) Dividend covers the period from April 15, 2016, to July 14, 2016.

Dividend covers the period from July 15, 2016, to October 14, 2016.

XML

Noncontrolling Interests - Operating Partnership (Tables)

9 Months Ended

Sep. 30, 2016

Noncontrolling Interests - Operating Partnership

Schedule of ownership interests in our Operating Partnership

	September 30, 2016			December 31, 2015
	Number of Units	Percentage of Total		Number of Units	Percentage of Total
CoreSite Realty Corporation	33,371,340	70.7	%	30,136,556	64.1	%
Noncontrolling interests	13,851,347	29.3		16,858,347	35.9
Total	47,222,687	100.0	%	46,994,903	100.0	%

XML

Equity Incentive Plan (Tables)

9 Months Ended

Sep. 30, 2016

Equity Incentive Plan

Schedule of stock option activity

	Number of
	Shares	Weighted-
	Subject to	Average
	Option	Exercise Price
Options outstanding, December 31, 2015	340,210	$	21.77
Granted	—		—
Exercised	(71,609)		17.35
Forfeited	—		—
Expired	—		—
Options outstanding, September 30, 2016	268,601	$	22.95

Schedule of unvested shares subject to options

	Number of	Weighted-
	Shares	Average Fair
	Subject to	Value at Grant
	Option	Date
Unvested balance, December 31, 2015	105,267	$	9.13
Granted	—		—
Forfeited	—		—
Vested	(88,944)		8.97
Unvested balance, September 30, 2016	16,323	$	9.99

Schedule of restricted awards and RSUs

		Weighted-
	Restricted	Average Fair
	Awards and	Value at Grant
	Units	Date
Unvested balance, December 31, 2015	377,612	$	38.51
Granted	179,511		66.69
Forfeited	(35,046)		53.86
Vested	(196,708)		36.62
Unvested balance, September 30, 2016	325,369	$	53.55

Schedule of unvested PSAs and their weighted-average fair value at the date of grant

				Weighted-
				Average Fair
	Performance-Based Restricted Stock Awards			Value at Grant
	Minimum	Maximum	Target	Date
Unvested balance, December 31, 2015	10,203	142,963	92,802	$	42.78
Granted	11,796	82,572	47,184		84.78
Forfeited	(7,988)	(55,916)	(31,952)		69.12
Vested	(125)	(1,894)	(1,180)		42.17
Unvested balance, September 30, 2016	13,886	167,725	106,854	$	54.24

Summary of assumptions used to value performance stock awards

	Nine Months Ended September 30,
	2016		2015
Expected term (in years)	2.83		2.83
Expected volatility	25.29	%	25.51	%
Expected annual dividend(1)	—		—
Risk-free rate	0.97	%	1.02	%

The fair value of the PSAs assumes reinvestment of dividends.

XML

Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2016

Earnings Per Share

Summary of basic and diluted income per share

The following is a summary of basic and diluted net income per share (in thousands, except share and per share amounts):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Net income attributable to common shares	$	12,180	$	6,920	$	35,476	$	17,026
Weighted-average common shares outstanding - basic		33,425,762		26,126,332		31,906,000		24,029,106
Effect of potentially dilutive common shares:
Stock options		192,272		238,386		197,166		329,833
Unvested awards		294,121		184,819		258,201		185,673
Weighted-average common shares outstanding - diluted		33,912,155		26,549,537		32,361,367		24,544,612
Net income per share attributable to common shares
Basic	$	0.36	$	0.26	$	1.11	$	0.71
Diluted	$	0.36	$	0.26	$	1.10	$	0.69

XML

Organization and Description of Business (Details) - Operating partnership	Sep. 30, 2016
Organization
Percentage of ownership interests held by the entity	70.70%
Percentage of ownership interests held by others	29.30%

XML

Summary of Significant Accounting Policies - Real Estate (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments in Real Estate
Capitalized interest costs	$ 1.6	$ 0.6	$ 3.5	$ 2.9
Depreciation expense	$ 22.3	$ 19.6	$ 63.9	$ 56.7
Building | Minimum
Investments in Real Estate
Useful lives			27 years
Building | Maximum
Investments in Real Estate
Useful lives			40 years
Building Improvements | Minimum
Investments in Real Estate
Useful lives			1 year
Building Improvements | Maximum
Investments in Real Estate
Useful lives			10 years

XML

Summary of Significant Accounting Policies - Deferred Costs & Impairment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Summary of Significant Accounting Policies
Impairment loss related to intangible assets	$ 0	$ 0	$ 0	$ 0
Goodwill	41,191		41,191		$ 41,191
Impairment loss related to goodwill	0	0	0	0
Deferred Costs
Internal sales commissions	18,678		18,678		17,558
Third party commissions	13,910		13,910		15,866
External legal counsel	740		740		718
Total	33,328		33,328		$ 34,142
Recoverability of Long-Lived Assets
Impairment of real estate	$ 0	$ 0	$ 0	$ 0

XML

Summary of Significant Accounting Policies - Internal Use Software, RR & IT (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Internal-Use Software
Recognized impairment of internal use software	$ 0	$ 0	$ 0	$ 0
Revenue Recognition
Increase to rental revenue	100		400
Allowance for doubtful accounts (in dollars)	97		97		$ 56
Asset Retirement and Environmental Remediation Obligations
Asset retirement and environmental remediation obligations	1,400		$ 1,400		$ 1,700
Income taxes
Minimum percentage of distribution of taxable income to qualify as REIT			90.00%
Percentage of distribution of taxable income as per company policy			100.00%
Provision for federal income taxes			$ 0
Liabilities for uncertain positions	$ 0		$ 0

XML

Summary of Significant Accounting Policies - Concentration of Credit Risks & Segment Information (Details)	9 Months Ended
	Sep. 30, 2016 segment item
Summary of Significant Accounting Policies
Number of off-balance-sheet concentrations of credit risk | item	0
Segment information
Number of reportable segments | segment	1

XML

Investment in Real Estate (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2015
Investment in Real Estate
Land		$ 82,463	$ 74,819
Buildings and Improvements		1,186,712	1,037,127
Construction in progress		272,928	$ 183,189
Total investments in real estate		1,542,103
Gain on real estate disposal	$ 36
Boston
Investment in Real Estate
Land		5,154
Buildings and Improvements		96,202
Construction in progress		459
Total investments in real estate		101,815
Chicago
Investment in Real Estate
Land		5,493
Buildings and Improvements		98,549
Construction in progress		2,159
Total investments in real estate		106,201
Denver
Investment in Real Estate
Buildings and Improvements		4,878
Construction in progress		2,068
Total investments in real estate		6,946
Los Angeles
Investment in Real Estate
Land		28,467
Buildings and Improvements		232,825
Construction in progress		3,439
Total investments in real estate		264,731
Miami
Investment in Real Estate
Land		728
Buildings and Improvements		10,482
Construction in progress		2
Total investments in real estate		11,212
New York
Investment in Real Estate
Land		2,388
Buildings and Improvements		127,842
Construction in progress		38,096
Total investments in real estate		168,326
Northern Virginia
Investment in Real Estate
Land		12,442
Buildings and Improvements		246,606
Construction in progress		7,380
Total investments in real estate		266,428
San Francisco Bay
Investment in Real Estate
Land		27,791
Buildings and Improvements		369,328
Construction in progress		219,325
Total investments in real estate		$ 616,444

XML

Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Other Assets.
Deferred leasing costs	$ 33,328	$ 34,142
Deferred rent receivable	31,215	29,309
Internal-use software	13,010	10,467
Prepaid expense	6,415	2,689
Corporate furniture, fixtures and equipment	5,556	6,157
Deferred financing costs	1,766	2,251
Other	4,984	1,618
Total	96,274	86,633
Estimated amortization of deferred leasing costs
Total	$ 33,328	$ 34,142

XML

Debt - Summary of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Debt
Total principal outstanding	$ 594,750	$ 392,250
Unamortized deferred financing costs	(3,758)	(1,243)
Total debt	$ 590,992	$ 391,007
Revolving Credit Facility
Debt
Interest rate as of reporting date (as a percent)	2.08%	1.98%
Total principal outstanding	$ 94,750	$ 142,250
2019 Senior Unsecured Term Loan | Senior Unsecured Term Loan
Debt
Interest rate as of reporting date (as a percent)	3.23%	3.23%
Total principal outstanding	$ 100,000	$ 100,000
2020 Senior Unsecured Term Loan | Senior Unsecured Term Loan
Debt
Interest rate as of reporting date (as a percent)	2.48%	2.43%
Total principal outstanding	$ 150,000	$ 150,000
2021 Senior Unsecured Term Loan | Senior Unsecured Term Loan
Debt
Interest rate as of reporting date (as a percent)	2.03%
Total principal outstanding	$ 100,000
2023 Senior Unsecured Term Loan | Senior Unsecured Notes
Debt
Interest rate as of reporting date (as a percent)	4.19%
Total principal outstanding	$ 150,000
Operating partnership | 2019 Senior Unsecured Term Loan | Interest Rate Swap
Debt
Amount borrowed under term loan or revolving credit facility	$ 100,000
Percentage of debt hedged	100.00%
Derivative, Fixed Interest Rate	3.23%
Operating partnership | 2020 Senior Unsecured Term Loan | Interest Rate Swap
Debt
Interest rate as of reporting date (as a percent)	2.48%
Amount borrowed under term loan or revolving credit facility	$ 75,000
Percentage of debt hedged	50.00%
Derivative, Fixed Interest Rate	2.93%

XML

Debt - Revolving Credit Facility (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($) item	Feb. 02, 2016 USD ($)	Jun. 24, 2015 USD ($)
Credit Agreement
Debt
Leverage ratio (as a percent)	20.70%
Secured debt ratio (as a percent)	0.00%
Fixed charge coverage ratio	8.1
Unhedged variable rate debt ratio (as a percent)	9.30%
Credit Agreement | Minimum
Debt
Fixed charge coverage ratio	1.70
Credit Agreement | Maximum
Debt
Leverage ratio (as a percent)	0.60%
Secured debt ratio (as a percent)	0.40%
Unhedged variable rate debt ratio (as a percent)	0.30%
Operating partnership | LIBOR
Debt
Interest rate margin (as a percent)	1.55%
Operating partnership | Credit Agreement
Debt
Number of options available for extensions | item	1
Extension fee (as a percent)	0.10%
Maximum borrowing capacity		$ 600.0	$ 500.0
Unsecured term loan		100.0
Increase in accordion feature borrowing capacity		100.0
Maximum borrowing capacity including accordion feature		$ 800.0	700.0
Borrowing capacity at end of period	$ 350.0
Letters of credit outstanding	4.5
Amount available for borrowing under the facility	250.8
Operating partnership | Credit Agreement | Revolving Credit Facility
Debt
Maximum borrowing capacity			350.0
Borrowed and outstanding	$ 94.8
Leverage ratio (as a percent)	20.70%
Operating partnership | Credit Agreement | Revolving Credit Facility | LIBOR | Minimum
Debt
Interest rate margin (as a percent)	1.55%
Operating partnership | Credit Agreement | Revolving Credit Facility | LIBOR | Maximum
Debt
Interest rate margin (as a percent)	2.25%
Operating partnership | Credit Agreement | Revolving Credit Facility | Base Rate | Minimum
Debt
Interest rate margin (as a percent)	0.55%
Operating partnership | Credit Agreement | Revolving Credit Facility | Base Rate | Maximum
Debt
Interest rate margin (as a percent)	1.25%
Operating partnership | Credit Agreement | Senior Unsecured Term Loan
Debt
Unsecured term loan			150.0
Operating partnership | Prior Facility
Debt
Maximum borrowing capacity			$ 405.0

XML

Debt - Unsecured Debt (Details) - Operating partnership - USD ($) $ in Millions				9 Months Ended
	Feb. 02, 2016	Jun. 24, 2015	Jan. 31, 2014	Sep. 30, 2016	Jun. 15, 2016
LIBOR
Debt
Interest rate margin (as a percent)				1.55%
2019 Senior Unsecured Term Loan
Debt
Leverage ratio (as a percent)				20.70%
2019 Senior Unsecured Term Loan | LIBOR
Debt
Interest rate margin (as a percent)				1.75%
2019 Senior Unsecured Term Loan | LIBOR | Minimum
Debt
Interest rate margin (as a percent)				1.75%
2019 Senior Unsecured Term Loan | LIBOR | Maximum
Debt
Interest rate margin (as a percent)				2.65%
2019 Senior Unsecured Term Loan | Base Rate | Minimum
Debt
Interest rate margin (as a percent)				0.75%
2019 Senior Unsecured Term Loan | Base Rate | Maximum
Debt
Interest rate margin (as a percent)				1.65%
2019 Senior Unsecured Term Loan | Senior Unsecured Term Loan
Debt
Unsecured term loan			$ 100
Term of loan facility			5 years
Increase in accordion feature borrowing capacity			$ 100
Accordion feature			$ 200
2020 Senior Unsecured Term Loan
Debt
Leverage ratio (as a percent)				20.70%
2020 Senior Unsecured Term Loan | LIBOR
Debt
Interest rate margin (as a percent)				1.50%
2020 Senior Unsecured Term Loan | LIBOR | Minimum
Debt
Interest rate margin (as a percent)				1.50%
2020 Senior Unsecured Term Loan | LIBOR | Maximum
Debt
Interest rate margin (as a percent)				2.20%
2020 Senior Unsecured Term Loan | Base Rate | Minimum
Debt
Interest rate margin (as a percent)				0.50%
2020 Senior Unsecured Term Loan | Base Rate | Maximum
Debt
Interest rate margin (as a percent)				1.20%
2020 Senior Unsecured Term Loan | Senior Unsecured Term Loan
Debt
Unsecured term loan		$ 150
Term of loan facility		5 years
2021 Senior Unsecured Term Loan
Debt
Leverage ratio (as a percent)				20.70%
2021 Senior Unsecured Term Loan | LIBOR
Debt
Interest rate margin (as a percent)				1.50%
2021 Senior Unsecured Term Loan | LIBOR | Minimum
Debt
Interest rate margin (as a percent)				1.50%
2021 Senior Unsecured Term Loan | LIBOR | Maximum
Debt
Interest rate margin (as a percent)				2.20%
2021 Senior Unsecured Term Loan | Base Rate | Minimum
Debt
Interest rate margin (as a percent)				0.50%
2021 Senior Unsecured Term Loan | Base Rate | Maximum
Debt
Interest rate margin (as a percent)				1.20%
2021 Senior Unsecured Term Loan | Senior Unsecured Term Loan
Debt
Unsecured term loan	$ 100
Term of loan facility	5 years
2023 Senior Unsecured Term Loan | Senior Unsecured Notes | Private Placement
Debt
Aggregate principal amount					$ 150
Stated interest rate					4.19%
Percentage of term notes that may be prepaid					100.00%
Percentage of term notes that holders have right to purchase in cash					100.00%
Percentage of term notes that holders may redeem for cash					100.00%

XML

Debt - Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Debt maturities
2019	$ 194,750
2020	150,000
Thereafter	250,000
Total principal outstanding	594,750	$ 392,250
Unamortized deferred financing costs	(3,758)	(1,243)
Total debt	$ 590,992	$ 391,007

XML

Derivatives and Hedging Activities (Details) - USD ($)			3 Months Ended		9 Months Ended		12 Months Ended
	Apr. 09, 2015	Feb. 03, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 2017	Dec. 31, 2015
Derivative instruments and hedging activities disclosures
Amount of gain (loss) recorded in accumulated other comprehensive income			$ 824,000	$ (2,947,000)	$ (3,597,000)	$ (3,807,000)
Cash Flow Hedging
Derivative instruments and hedging activities disclosures
Earnings related to derivatives due to hedge ineffectiveness			0	0	0	0
Interest Rate Swap | Designated as Hedging Instrument | Cash Flow Hedging
Derivative instruments and hedging activities disclosures
Amount borrowed under term loan or revolving credit facility	$ 75,000,000	$ 100,000,000
Term of loan facility	5 years	5 years
Derivative, Fixed Interest Rate	2.93%	3.23%
Amount of gain (loss) recorded in accumulated other comprehensive income			(800,000)	2,900,000	(3,600,000)	(3,800,000)
Amount reclassified to interest expense			400,000	$ 600,000	1,300,000	$ 1,400,000
Amount recognized in unearned revenue, prepaid rent and other liabilities			$ 3,000,000		$ 3,000,000			$ 800,000
Interest Rate Swap | Designated as Hedging Instrument | Cash Flow Hedging | Forecast
Derivative instruments and hedging activities disclosures
Amount estimated to be reclassified as an increase to interest expense							$ 1,700,000
LIBOR | Interest Rate Swap | Designated as Hedging Instrument | Cash Flow Hedging
Derivative instruments and hedging activities disclosures
Reference rate	one-month LIBOR

XML

Stockholders' Equity (Details) - $ / shares				9 Months Ended
	Oct. 17, 2016	Jul. 15, 2016	Apr. 15, 2016	Sep. 30, 2016
Series A Cumulative Redeemable Preferred Stock
Stockholders' Equity
Dividends Payable, Date of Record		Sep. 30, 2016	Mar. 31, 2016
Dividends paid on preferred stock (per share)		$ 0.4531	$ 0.4531	$ 1.3593
Preferred stock dividend declared (per share)	$ 0.4531
Common Stock
Stockholders' Equity
Dividends Payable, Date of Record	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2016
Dividends paid on common stock (per share)		$ 0.53	$ 0.53	$ 1.59
Common Stock dividend declared (per share)	$ 0.53

XML

Noncontrolling Interests - Operating Partnership (Details) $ / shares in Units, $ in Thousands			9 Months Ended	12 Months Ended
	May 13, 2016 USD ($) shares	Dec. 12, 2012 shares	Sep. 30, 2016 USD ($) $ / shares shares	Dec. 31, 2015 shares
Noncontrolling Interests - Operating Partnership
Series A Cumulative Preferred Stock, dividend rate (as a percent)			7.25%	7.25%
Noncontrolling Interests
Noncontrolling Interests - Operating Partnership
Reduction to noncontrolling interests in the Operating Partnership and an increase to common stock and additional paid in capital | $			$ 37,374
Operating partnership
Noncontrolling Interests - Operating Partnership
Conversion ratio for common operating partnership units			1
Preferred Operating Partnership units issued to CoreSite Realty Corporation (in shares)		4,600,000
Series A Cumulative Preferred Stock, dividend rate (as a percent)		7.25%
Number of Operating Partnership Units (in shares)			47,222,687	46,994,903
Percentage of Total			70.70%
Percentage of Total			29.30%
Percentage of Total			100.00%	100.00%
Shares of common stock issued related to employee compensation arrangements			227,784
Quarterly distributions will receive by holders of operating partnership units (in dollars per unit) | $ / shares			$ 0.53
Common Operating Partnership units redeemed for common stock (in shares)			3,007,000
Redemption of noncontrolling interests (in shares)	3,007,000
Reduction to noncontrolling interests in the Operating Partnership and an increase to common stock and additional paid in capital | $	$ 37,400
Operating partnership | Coresite Realty Corporation
Noncontrolling Interests - Operating Partnership
Number of Operating Partnership Units (in shares)			33,371,340	30,136,556
Percentage of Total			70.70%	64.10%
Operating partnership | Noncontrolling Interests
Noncontrolling Interests - Operating Partnership
Number of Operating Partnership Units (in shares)			13,851,347	16,858,347
Percentage of Total			29.30%	35.90%
Redemption value of the noncontrolling interests | $			$ 1,000,000
Closing price of the Company's stock (in dollars per share) | $ / shares			$ 74.04

XML

Equity Incentive Plan (Details) - 2010 Plan - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Equity Incentive Plan
Shares of common stock reserved for issuance	6,000,000
Shares of common stock that were available for issuance	3,109,969
Stock Options
Number of Shares Subject to Option
Options outstanding at the beginning of the period (in shares)	340,210
Exercised (in shares)	(71,609)
Options outstanding at the end of the period (in shares)	268,601
Weighted Average Exercise Price
Options outstanding at the beginning of the period (in dollars per share)	$ 21.77
Exercised (in dollars per share)	17.35
Options outstanding at the end of the period (in dollars per share)	$ 22.95
Number of Shares Subject to Option
Unvested balance at the beginning of the period (in shares)	105,267
Vested (in shares)	(88,944)
Unvested balance at the end of the period (in shares)	16,323
Weighted Average Fair Value at Grant
Unvested balance at the beginning of the period (in dollars per share)	$ 9.13
Vested (in dollars per share)	8.97
Unvested balance at the end of the period (in dollars per share)	$ 9.99
Compensation cost not yet recognized
Unearned compensation	$ 0.1
Stock Options | Weighted Average
Compensation cost not yet recognized
Vesting period	4 months 24 days
Restricted Awards
Restricted Awards and PSA's
Unvested balance at the beginning of the period (in shares)	377,612
Granted (in shares)	179,511
Forfeited (in shares)	(35,046)
Vested (in shares)	(196,708)
Unvested balance at the end of the period (in shares)	325,369
Weighted Average Fair Value at Grant
Unvested balance at the beginning of the period (in dollars per share)	$ 38.51
Granted (in dollars per share)	66.69
Forfeited (in dollars per share)	53.86
Vested (in dollars per share)	36.62
Unvested balance at the end of the period (in dollars per share)	$ 53.55
Compensation cost not yet recognized
Unearned compensation	$ 13.9
Restricted Awards | Weighted Average
Compensation cost not yet recognized
Vesting period	2 years 7 months 6 days
PSAs
Weighted Average Fair Value at Grant
Unvested balance at the beginning of the period (in dollars per share)	$ 42.78
Granted (in dollars per share)	84.78
Forfeited (in dollars per share)	69.12
Vested (in dollars per share)	42.17
Unvested balance at the end of the period (in dollars per share)	$ 54.24
Compensation cost not yet recognized
Unearned compensation	$ 3.3
Number of awards which failed to satisfy performance condition	0	6,444
Assumptions used to value the stock options granted
Expected term	2 years 9 months 29 days	2 years 9 months 29 days
Expected volatility (as a percent)	25.29%	25.51%
Risk-free rate (as a percent)	0.97%	1.02%
PSAs | Weighted Average
Compensation cost not yet recognized
Vesting period	2 years 2 months 12 days
PSAs | Minimum
Restricted Awards and PSA's
Unvested balance at the beginning of the period (in shares)	10,203
Granted (in shares)	11,796
Forfeited (in shares)	(7,988)
Vested (in shares)	(125)
Unvested balance at the end of the period (in shares)	13,886
Compensation cost not yet recognized
Percentage of target number of shares for PSAs granted in 2014	0.00%
Percentage of target number of shares for PSAs granted in years 2015 and 2016	25.00%
Assumptions used to value the stock options granted
Performance period	1 year
PSAs | Maximum
Restricted Awards and PSA's
Unvested balance at the beginning of the period (in shares)	142,963
Granted (in shares)	82,572
Forfeited (in shares)	(55,916)
Vested (in shares)	(1,894)
Unvested balance at the end of the period (in shares)	167,725
Compensation cost not yet recognized
Percentage of target number of shares for PSAs granted in 2014	150.00%
Percentage of target number of shares for PSAs granted in years 2015 and 2016	175.00%
Assumptions used to value the stock options granted
Performance period	3 years
PSAs | Target
Restricted Awards and PSA's
Unvested balance at the beginning of the period (in shares)	92,802
Granted (in shares)	47,184
Forfeited (in shares)	(31,952)
Vested (in shares)	(1,180)
Unvested balance at the end of the period (in shares)	106,854

XML

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share
Net income attributable to common shares	$ 12,180	$ 6,920	$ 35,476	$ 17,026
Weighted-average common shares outstanding - basic	33,425,762	26,126,332	31,906,000	24,029,106
Effect of potentially dilutive common shares:
Stock options	192,272	238,386	197,166	329,833
Unvested awards	294,121	184,819	258,201	185,673
Weighted-average common shares outstanding - diluted	33,912,155	26,549,537	32,361,367	24,544,612
Net income per share attributable to common shares
Basic (in dollars per share)	$ 0.36	$ 0.26	$ 1.11	$ 0.71
Diluted (in dollars per share)	$ 0.36	$ 0.26	$ 1.10	$ 0.69
Weighted-average potentially dilutive securities excluded in calculation of basic and diluted income (loss) per share	7,757	40,565	113,920	157,534

XML

Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Estimated Fair Value of Financial Instruments
Total principal outstanding	$ 594,750	$ 392,250
Significant Unobservable Inputs (Level 3)
Estimated Fair Value of Financial Instruments
Total principal outstanding	$ 594,800	$ 392,300

XML

Commitments and Contingencies (Details)			9 Months Ended
	Jul. 22, 2016 USD ($)	Jul. 23, 2015 USD ($)	Sep. 30, 2016 USD ($)	Aug. 11, 2016 USD ($) a
Accounts Payable and Accrued Expenses
Commitments and Contingencies
Accrued Litigation Liability			$ 2,900,000
Telecommunications Capacity
Commitments and Contingencies
Open commitments			9,600,000
Construction Contracts
Commitments and Contingencies
Open commitments			49,800,000
Pending Litigation
Commitments and Contingencies
Estimated Loss Contingency, Minimum			600,000
Estimated Loss Contingency, Maximum			3,100,000
Pending Litigation | Damages Related To Services Rendered
Commitments and Contingencies
Loss Contingency, Damages Sought	$ 600,000	$ 802,564
Pending Litigation | Damages For Loss Of Revenue And Other Costs
Commitments and Contingencies
Loss Contingency, Damages Sought		$ 70,080,000
Commonwealth Of Virginia | Minimum
Commitments and Contingencies
Estimated sales and use tax liability			0
Commonwealth Of Virginia | Maximum
Commitments and Contingencies
Potential sales and use tax liability, if certain thresholds are not met			7,500,000
Estimated sales and use tax liability			$ 4,000,000
Sunrise Technology Park Reston VA
Commitments and Contingencies
Area of Real Estate Property | a				21.75
Purchase price				$ 65,100,000