Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIESPRINCIPLES OF CONSOLIDATIONThe accompanying financial statements reflect our financial position, results of operations, comprehensive income (loss), equity and cash flows on a consolidated basis. All intercompany transactions and account balances have been eliminated.USE OF ESTIMATESThe preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires us to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities at the date of the financial statements and for the period then ended. On an ongoing basis, we evaluate the estimates used. We base our estimates on historical experience, actuarial estimates, current conditions and various other assumptions that we believe to be reasonable under the circumstances. These estimates form the basis for making judgments about the carrying values of assets and liabilities and are not readily apparent from other sources. Actual results may differ from these estimates.

C. FOREIGN CURRENCY

Local currencies are the functional currencies for our operations outside the United States, with the exception of certain foreign holding companies, whose functional currency is the United States dollar. In those instances where the local currency is the functional currency, assets and liabilities are translated at period-end exchange rates, and revenues and expenses are translated at average exchange rates for the applicable period. See Note 2.q.

D. CASH, CASH EQUIVALENTS AND RESTRICTED CASH

Cash and cash equivalents include cash on hand and cash invested in highly liquid short-term securities, which have remaining maturities at the date of purchase of less than 90 days. Cash and cash equivalents are carried at cost, which approximates fair value.

E. ALLOWANCE FOR DOUBTFUL ACCOUNTS AND CREDIT MEMO RESERVES

We maintain an allowance for doubtful accounts and a credit memo reserve for estimated losses resulting from the potential inability of our customers to make required payments and potential disputes regarding billing and service issues.

In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2016-13, Financial Instruments-Credit Losses-Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 changes how entities will measure credit losses on most financial assets. The standard eliminates the probable initial recognition of estimated losses and provides a forward-looking expected credit loss model for accounts receivable, loans and other financial instruments.

On January 1, 2020 we adopted ASU 2016-13 on a modified retrospective basis for all financial assets measured at amortized cost. The adoption of ASU 2016-13 did not result in a material impact on our consolidated financial statements. Under ASU 2016-13, we calculate and monitor our allowance considering future potential economic and macroeconomic conditions and reasonable and supportable forecasts for expected future collectability of our outstanding receivables, in addition to considering our past loss experience, current and prior trends in our aged receivables and credit memo activity. Our considerations when calculating our allowance include, but are not limited to, the following: the location of our businesses, the composition of our customer base, our product and service lines, potential future economic unrest, and potential future macroeconomic factors, including natural disasters and any impacts associated with the COVID-19 pandemic. Continued adjustments will be made should there be any material change to reasonable and supportable forecasts that may impact our likelihood of collection, as it becomes evident. Our highly diverse global customer base, with no single customer accounting for more than 1% of revenue during the years ended December 31, 2020, 2019 and 2018, limits our exposure to concentration of credit risk. Additionally, we write off uncollectible balances as circumstances warrant, generally, no later than one year past due.

Prior to our adoption of ASU 2016-13, we maintained an allowance for doubtful accounts for estimated losses resulting from the potential inability of our customers to make required payments and potential disputes regarding billing and service issues. When calculating the allowance, we considered our past loss experience, current and prior trends in our aged receivables and credit memo activity, current economic conditions, and specific circumstances of individual receivable balances. If the financial condition of our customers were to significantly change, resulting in a significant improvement or impairment of their ability to make payments, an adjustment of the allowance might have been required.

Rollforward of allowance for doubtful accounts and credit memo reserves is as follows:

YEAR ENDED DECEMBER 31,	BALANCE AT BEGINNING OF THE YEAR		CREDIT MEMOS CHARGED TO REVENUE		ALLOWANCE FOR BAD DEBTS CHARGED TO EXPENSE		DEDUCTIONS AND OTHER(1)		BALANCE AT END OF THE YEAR
2020	$	42,856	$	55,118	$	34,411	$	(75,404)	$	56,981
2019	43,584		51,846		19,389		(71,963)		42,856
2018	46,648		36,329		18,625		(58,018)		43,584

(1)Primarily consists of the issuance of credit memos, the write-off of accounts receivable and the impact associated with currency translation adjustments.

F. CONCENTRATIONS OF CREDIT RISK

Financial instruments that potentially subject us to credit risk consist principally of cash and cash equivalents (including money market funds and time deposits) and accounts receivable. The only significant concentrations of liquid investments as of December 31, 2020 and 2019 related to cash and cash equivalents. At December 31, 2020, we had money market funds with four “Triple A” rated money market funds and time deposits with one global bank. At December 31, 2019, we had money market funds with seven “Triple A” rated money market funds. As per our risk management investment policy, we limit exposure to concentration of credit risk by limiting the amount invested in any one mutual fund to a maximum of 1% of the fund's total assets or in any one financial institution to a maximum of $75,000. See Note 2.o.

G. PREPAID EXPENSES AND ACCRUED EXPENSES

There are no prepaid expenses with items greater than 5% of total current assets as of December 31, 2020 and 2019.

Accrued expenses, with items greater than 5% of total current liabilities are shown separately, and consist of the following:

	DECEMBER 31,
DESCRIPTION	2020		2019
Interest	$	131,448	$	97,987
Sales tax and VAT payable	131,780		115,352
Dividends	187,867		186,021
Operating lease liabilities	250,239		223,249
Other	444,954		339,143
Accrued expenses	$	1,146,288	$	961,752

H. PROPERTY, PLANT AND EQUIPMENT

Property, plant and equipment are stated at cost and depreciated using the straight-line method with the following useful lives (in years):

DESCRIPTION	RANGE
Buildings and building improvements	5 to 40
Leasehold improvements	5 to 10 or life of the lease (whichever is shorter)
Racking	1 to 20 or life of the lease (whichever is shorter)
Warehouse equipment/vehicles	1 to 10
Furniture and fixtures	1 to 10
Computer hardware and software	2 to 5

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

Property, plant and equipment (including financing leases in the respective category), at cost, consist of the following:

	DECEMBER 31,
DESCRIPTION	2020		2019
Land	$	354,395	$	448,566
Buildings and building improvements	3,040,253		3,029,309
Leasehold improvements	969,273		852,022
Racking	2,083,199		2,040,832
Warehouse equipment/vehicles	499,787		483,218
Furniture and fixtures	52,978		54,275
Computer hardware and software	746,993		689,261
Construction in progress	499,459		451,423
Property, plant and equipment	$	8,246,337	$	8,048,906

Minor maintenance costs are expensed as incurred. Major improvements which extend the life, increase the capacity or improve the safety or the efficiency of property owned are capitalized and depreciated. Major improvements to leased buildings are capitalized as leasehold improvements and depreciated.

We capitalize interest expense during the active construction period of major capital projects. Capitalized interest is added to the cost of the underlying assets and is amortized over the useful lives of the assets. During the years ended December 31, 2020, 2019 and 2018, capitalized interest is as follows:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Capitalized interest	$	14,321	$	15,980	$	3,732

We develop various software applications for internal use. Computer software costs associated with internal use software are expensed as incurred until certain capitalization criteria are met. Third party consulting costs, as well as payroll and related costs for employees directly associated with, and devoting time to, the development of internal use computer software projects (to the extent time is spent directly on the project) are capitalized. Capitalization begins when the design stage of the application has been completed and it is probable that the project will be completed and used to perform the function intended. Capitalization ends when the asset is ready for its intended use. Depreciation begins when the software is placed in service. Computer software costs that are capitalized are periodically evaluated for impairment.

During the years ended December 31, 2020, 2019 and 2018, capitalized costs associated with the development of internal use computer software projects are as follows:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Capitalized costs associated with the development of internal use computer software projects	$	38,329	$	34,650	$	29,407

Entities are required to record the fair value of a liability for an asset retirement obligation in the period in which it is incurred. Asset retirement obligations represent the costs to replace or remove tangible long-lived assets required by law, regulatory rule or contractual agreement. Our asset retirement obligations are primarily the result of requirements under our facility lease agreements which generally have “return to original condition” clauses which would require us to remove or restore items such as shred pits, vaults, demising walls and office build-outs, among others. The significant assumptions used in estimating our aggregate asset retirement obligations are the timing of removals, the probability of a requirement to perform, estimated cost and associated expected inflation rates that are consistent with historical rates and credit-adjusted risk-free rates that approximate our incremental borrowing rate. Our asset retirement obligations at December 31, 2020 and 2019 were $34,537 and $30,831, respectively.

I. LEASES

We lease facilities for certain warehouses, data centers and office space. We also have land leases, including those on which certain facilities are located. The majority of our leased facilities are classified as operating leases that, on average, have initial lease terms of five to 10 years, with one or more lease renewal options to extend the lease term. Our lease renewal option terms generally range from one to five years. The exercise of the lease renewal option is at our sole discretion and may contain fixed rent, fair market value based rent or Consumer Price Index rent escalation clauses. We include option periods in the lease term when our failure to renew the lease would result in an economic disincentive, thereby making it reasonably certain that we will renew the lease. We recognize straight line rental expense over the life of the lease and any fair market value or Consumer Price Index rent escalations are recognized as variable lease expense in the period in which the obligation is incurred. In addition, we lease certain vehicles and equipment. Vehicle and equipment leases typically have lease terms ranging from one to seven years.

We account for all leases, both operating and financing, in accordance with ASU No. 2016-02 Leases (Topic 842), as amended ("ASU 2016-02") which we adopted on January 1, 2019 on a modified retrospective basis. We also adopted an accounting policy which provides that leases with an initial term of 12 months or less will not be included within the lease right-of-use assets and lease liabilities recognized on our Consolidated Balance Sheets after the adoption of ASU 2016-02. We will continue to recognize the lease payments for those leases with an initial term of 12 months or less in our Consolidated Statements of Operations on a straight-line basis over the lease term.

The lease right-of-use assets and related lease liabilities are classified as either operating or financing. Lease right-of-use assets are calculated as the net present value of future payments plus any capitalized initial direct costs less any tenant improvements or lease incentives. Lease liabilities are calculated as the net present value of future payments. In calculating the present value of the lease payments, we utilize the rate stated in the lease (in the limited circumstances when such rate is explicitly stated) or, if no rate is explicitly stated, we utilize a rate that reflects our securitized incremental borrowing rate by geography for the lease term. We account for nonlease components (which include common area maintenance, taxes, and insurance) with the related lease component. Any variable nonlease components are not included within the lease right-of-use asset and lease liability on our Consolidated Balance Sheets, and instead, are reflected as an expense in the period incurred.

At January 1, 2019, we recognized the cumulative effect of initially applying ASU 2016-02 as an adjustment to the opening balance of (Distributions in excess of earnings) Earnings in excess of distributions, resulting in an increase of approximately $5,800 to stockholders’ equity due to certain build to suit leases that were accounted for as financing leases under Accounting Standards Codification (“ASC”) 840, Leases (“ASC 840”) but are accounted for as operating leases under ASU 2016-02.

Operating and financing lease right-of-use assets and lease liabilities as of December 31, 2020 and 2019 are as follows:

	DECEMBER 31,
DESCRIPTION	2020		2019
Assets:
Operating lease right-of-use assets(1)	$	2,196,502	$	1,869,101
Financing lease right-of-use assets, net of accumulated depreciation(2)(3)	310,534		327,215
Liabilities:
Current
Operating lease liabilities	$	250,239	$	223,249
Financing lease liabilities(3)	43,149		46,582
Long-term
Operating lease liabilities	2,044,598		1,728,686
Financing lease liabilities(3)	323,162		320,600

(1)At December 31, 2020 and 2019, these assets are comprised of approximately 99% real estate related assets (which include land, buildings and racking) and 1% non-real estate related assets (which include warehouse equipment, vehicles, furniture and fixtures and computer hardware and software).

(2)At December 31, 2020, these assets are comprised of approximately 72% real estate related assets and 28% non-real estate related assets. At December 31, 2019, these assets are comprised of approximately 69% real estate related assets and 31% non-real estate related assets.

(3)Financing lease right-of-use assets, current financing lease liabilities and long-term financing lease liabilities are included within Property, Plant and Equipment, Net, Current portion of long-term debt and Long-term Debt, net of current portion, respectively, within our Consolidated Balance Sheets.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

The components of the lease expense for the years ended December 31, 2020 and 2019 are as follows:

	YEAR ENDED DECEMBER 31,
DESCRIPTION	2020		2019
Operating lease cost(1)	$	499,464	$	459,619
Financing lease cost:
Depreciation of financing lease right-of-use assets	$	51,629	$	59,258
Interest expense for financing lease liabilities	19,942		21,031

(1)Operating lease cost, the majority of which is included in Cost of sales, includes variable lease costs of $111,501 and $105,922 for the years ended December 31, 2020 and 2019, respectively.

Weighted average remaining lease terms and discount rates as of December 31, 2020 and 2019 are as follows:

	DECEMBER 31, 2020				DECEMBER 31, 2019
	OPERATING LEASES		FINANCING LEASES		OPERATING LEASES		FINANCING LEASES
Remaining Lease Term	11.1 years		11.5 years		11.0 years		11.6 years
Discount Rate	6.9	%	5.9	%	7.1	%	5.7	%

The estimated minimum future lease payments as of December 31, 2020, are as follows:

YEAR	OPERATING LEASES(1)		SUBLEASE INCOME		FINANCING LEASES(1)
2021	$	380,607	$	(6,208)	$	62,669
2022	362,970		(5,752)		54,499
2023	334,893		(5,222)		45,557
2024	307,039		(3,771)		38,051
2025	281,487		(1,661)		32,261
Thereafter	1,687,706		(6,229)		268,542
Total minimum lease payments	3,354,702		$	(28,843)	501,579
Less amounts representing interest or imputed interest	(1,059,865)				(135,268)
Present value of lease obligations	$	2,294,837			$	366,311

(1)Estimated minimum future lease payments exclude variable common area maintenance charges, insurance and taxes.

At December 31, 2020, we had seven leases which we have signed but which have not yet commenced and are not included in our lease obligation table above. The total undiscounted minimum lease payments for these leases are approximately $236,200 and have lease terms that range from 10 to 25 years. Each of these leases is expected to commence during 2021, with the exception of one lease where the lease commencement date will be driven by the completion of the building construction, which is expected to occur by the end of 2021 or in early 2022.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

Other information: Supplemental cash flow information relating to our leases for the years ended December 31, 2020 and 2019 is as follows:

	YEAR ENDED DECEMBER 31,
CASH PAID FOR AMOUNTS INCLUDED IN MEASUREMENT OF LEASE LIABILITIES:	2020		2019
Operating cash flows used in operating leases	$	360,088	$	338,059
Operating cash flows used in financing leases (interest)	19,942		21,031
Financing cash flows used in financing leases	47,829		58,033
NON-CASH ITEMS:
Operating lease modifications and reassessments	$	143,382	$	108,023
New operating leases (including acquisitions and sale-leaseback transactions)	370,011		170,464

J. LONG-LIVED ASSETS

We review long-lived assets, including all finite-lived intangible assets, for impairment whenever events or changes in circumstances indicate the carrying amount of such assets may not be recoverable. Recoverability of these assets is determined by comparing the sum of the forecasted undiscounted net cash flows of the operation to which the assets relate to their carrying amount. The operations are generally distinguished by the business segment and geographic region in which they operate. If it is determined that we are unable to recover the carrying amount of the assets, the long-lived assets are written down, on a pro rata basis, to fair value. Fair value is determined based on discounted cash flows or appraised values, depending upon the nature of the assets. Long-lived assets, including finite-lived intangible assets, are amortized over their useful lives. Annually, or more frequently if events or circumstances warrant, we assess whether a change in the lives over which long-lived assets, including finite-lived intangible assets, are amortized is necessary.

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Consolidated gain on disposal/write-down of property, plant and equipment, net	$	363,537	$	63,824	$	73,622
The gains primarily consisted of:	•Gains associated with sale-leaseback transactions of approximately $342,100, of which (i) approximately $265,600 relates to the sale-leaseback transactions of 14 facilities in the United States during the fourth quarter of 2020 and (ii) approximately $76,400 relates to the sale-leaseback transactions of two facilities in the United States during the third quarter of 2020, each as part of our program to monetize a small portion of our industrial real estate assets. The terms for these leases are consistent with the terms of our lease portfolio, which are disclosed in Note 2.i. •Gains of approximately $24,100 associated with the Frankfurt JV Transaction (as defined in Note 3)		•Gains associated with sale and sale-leaseback transactions of approximately $67,800 in the United States •The sale of certain land and buildings of approximately $36,000 in the United Kingdom Partially offset by losses from: •The impairment charge on the assets associated with the select offerings within our Iron Mountain Iron Cloud ("Iron Cloud") portfolio and loss on the subsequent sale of certain IT infrastructure assets and rights to certain hardware and maintenance contracts used to deliver these Iron Cloud offerings of approximately $25,000. •The write-down of certain property, plant and equipment of approximately $15,700 in the United States.		•Gain on sale of real estate of approximately $63,800 in the United Kingdom •Gains associated with the involuntary conversion of assets included in a facility that we own in Argentina partially destroyed in a fire in 2014, of approximately $8,800 during the fourth quarter of 2018

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

K. GOODWILL AND OTHER INDEFINITE-LIVED INTANGIBLE ASSETS

Goodwill and intangible assets with indefinite lives are not amortized but are reviewed annually for impairment or more frequently if impairment indicators arise. Other than goodwill, we currently have no intangible assets that have indefinite lives and which are not amortized.

We have selected October 1 as our annual goodwill impairment review date. We have performed our annual goodwill impairment review as of October 1, 2020, 2019 and 2018. We concluded that as of October 1, 2020, 2019 and 2018, goodwill was not impaired. During the first quarter of 2020, as discussed in greater detail below, we concluded that we had a triggering event related to our Fine Arts reporting unit, requiring us to perform an interim goodwill impairment test. We concluded that the fair value of our Fine Arts reporting unit was less than its carrying value, and, therefore, we recorded a $23,000 impairment charge on the goodwill associated with this reporting unit during the first quarter of 2020.

The following is a discussion regarding (i) the reporting units at which level we tested goodwill for impairment as of October 1, 2019, (ii) changes to the composition of our reporting units between October 1, 2019 and December 31, 2019, (iii) interim goodwill impairment review for our Fine Arts reporting unit during the first quarter of 2020 and (iv) the reporting units at which level we tested goodwill for impairment as of October 1, 2020 and the composition of these reporting units at December 31, 2020 (including the amount of goodwill associated with each reporting unit). When changes occur in the composition of one or more reporting units, the goodwill is reassigned to the reporting units affected based upon their relative fair values.

GOODWILL IMPAIRMENT ANALYSIS - 2019

I. REPORTING UNITS AS OF OCTOBER 1, 2019

Our reporting units at which level we performed our goodwill impairment analysis as of October 1, 2019 were as follows:

•North American Records and Information Management •North American Data Management •Fine Arts •Entertainment Services •Western Europe •Northern/Eastern Europe and Middle East and India (“NEE and MEI”) •Latin America
•Australia, New Zealand and South Africa (“ANZ SA”) •Asia •Global Data Center

We concluded that the goodwill associated with each of our reporting units was not impaired as of such date.

II. CHANGES TO COMPOSITION OF REPORTING UNITS BETWEEN OCTOBER 1, 2019 AND DECEMBER 31, 2019

During the fourth quarter of 2019, as a result of the realignment of our global managerial structure and changes to our internal financial reporting associated with Project Summit, we reassessed the composition of our reportable operating segments (see Note 10 for a description and definitions of our reporting operating segments) as well as our reporting units.

We noted the following changes to our reporting units:

•our former North American Records and Information Management (excluding our technology escrow services business) and North American Data Management reporting units are now being managed as our “North America RIM” reporting unit;

•our former Western Europe and NEE and MEI reporting units (excluding India) and our business in Africa, which was previously managed as a component of our former ANZ SA reporting unit, is now being managed together as our “Europe RIM” reporting unit;

•our business in India, which was previously managed as a component of our former NEE and MEI reporting unit, is now being managed in conjunction with our businesses in Asia as our “Asia RIM” reporting unit;

•our former ANZ SA reporting unit will no longer include South Africa and will be referred to as our “Australia and New Zealand RIM” (“ANZ RIM”) reporting unit; and

•our technology escrow services business is now being managed separately as our “Technology Escrow Services” reporting unit.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

There were no changes to our Global Data Center, Fine Arts, Entertainment Services and Latin America RIM reporting units. We concluded that the goodwill associated with our North America RIM, Europe RIM, ANZ RIM, Asia RIM and Technology Escrow Services reporting units were not impaired following this change in reporting units.

GOODWILL BY REPORTING UNIT AS OF DECEMBER 31, 2019

The carrying value of goodwill, net for each of our reporting units described above as of December 31, 2019 is as follows:

SEGMENT	REPORTING UNIT	CARRYING VALUE AS OF DECEMBER 31, 2019
Global RIM (as defined in Note 10) Business	North America RIM	$	2,715,550
	Europe RIM	572,482
	Latin America RIM	140,897
	ANZ RIM	274,913
	Asia RIM	239,059
Global Data Center Business	Global Data Center	424,568
Corporate and Other Business	Fine Arts	37,533
	Entertainment Services	34,102
	Technology Escrow Services	46,105
Total		$	4,485,209

GOODWILL IMPAIRMENT ANALYSIS - 2020

I. INTERIM GOODWILL IMPAIRMENT REVIEW - FINE ARTS

During the first quarter of 2020, we concluded that we had a triggering event related to our Fine Arts reporting unit, requiring us to perform an interim goodwill impairment test. The primary factor contributing to our conclusion was the expected impact of the COVID-19 pandemic to this particular business and its customers and revenue sources, which caused us to believe it was more likely than not that the carrying value of our Fine Arts reporting unit exceeded its fair value. During the first quarter of 2020, we performed an interim goodwill impairment test for our Fine Arts reporting unit utilizing a discounted cash flow model, with updated assumptions on future revenues, operating expenditures and capital expenditures. We concluded that the fair value of our Fine Arts reporting unit was less than its carrying value, and, therefore, we recorded a $23,000 impairment charge on the goodwill associated with this reporting unit during the first quarter of 2020. Factors that may impact these assumptions include, but are not limited to: (i) our ability to maintain, or grow, storage and retail service revenues in this reporting unit in line with current expectations and (ii) our ability to manage our fixed and variable costs in this reporting unit in line with potential future revenue declines.

II. REPORTING UNITS AS OF OCTOBER 1, 2020

Our reporting units at which level we performed our goodwill impairment analysis as of October 1, 2020 were as follows:

•North America RIM •Europe RIM •Latin America RIM •ANZ RIM •Asia RIM •Global Data Center •Fine Arts •Entertainment Services •Technology Escrow Services

We concluded that the goodwill associated with each of our reporting units was not impaired as of such date. There were no changes to the composition of our reporting units between October 1, 2020 and December 31, 2020.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

GOODWILL BY REPORTING UNIT AS OF DECEMBER 31, 2020

The carrying value of goodwill, net for each of our reporting units described above as of December 31, 2020 is as follows:

SEGMENT	REPORTING UNIT	CARRYING VALUE AS OF DECEMBER 31, 2020
Global RIM Business	North America RIM	$	2,719,182
	Europe RIM	641,621
	Latin America RIM	117,834
	ANZ RIM	301,251
	Asia RIM	244,294
Global Data Center Business	Global Data Center	436,987
Corporate and Other Business	Fine Arts	15,176
	Entertainment Services	35,159
	Technology Escrow Services	46,105
Total		$	4,557,609

Reporting unit valuations have generally been determined using a combined approach based on the present value of future cash flows (the “Discounted Cash Flow Model”) and market multiples (the “Market Approach”).

The Discounted Cash Flow Model incorporates significant assumptions including future revenue growth rates, operating margins, discount rates and capital expenditures. The Market Approach requires us to make assumptions related to Adjusted EBITDA (as defined in Note 10) multiples.

Changes in economic and operating conditions impacting these assumptions or changes in multiples could result in goodwill impairments in future periods. In conjunction with our annual goodwill impairment reviews, we reconcile the sum of the valuations of all of our reporting units to our market capitalization as of such dates.

The changes in the carrying value of goodwill attributable to each reportable operating segment for the years ended December 31, 2020 and 2019 are as follows:

	GLOBAL RIM BUSINESS		GLOBAL DATA CENTER BUSINESS		CORPORATE AND OTHER BUSINESS		TOTAL CONSOLIDATED
Goodwill balance, net of accumulated amortization, as of December 31, 2018	$	3,899,210	$	425,956	$	115,864	$	4,441,030
Tax deductible goodwill acquired during the year	16,450		—		—		16,450
Non-tax deductible goodwill acquired during the year	11,228		—		1,904		13,132
Fair value and other adjustments	4,439		258		(417)		4,280
Currency effects	11,574		(1,646)		389		10,317
Goodwill balance, net of accumulated amortization, as of December 31, 2019	3,942,901		424,568		117,740		4,485,209
Non-tax deductible goodwill acquired during the year	54,258		—		—		54,258
Goodwill impairment	—		—		(23,000)		(23,000)
Fair value and other adjustments	(3,815)		—		403		(3,412)
Currency effects	30,838		12,419		1,297		44,554
Goodwill balance, net of accumulated amortization, as of December 31, 2020	$	4,024,182	$	436,987	$	96,440	$	4,557,609
Accumulated Goodwill Impairment Balance as of December 31, 2019	$	132,409	$	—	$	3,011	$	135,420
Accumulated Goodwill Impairment Balance as of December 31, 2020	$	132,409	$	—	$	26,011	$	158,420

L. FINITE-LIVED INTANGIBLE ASSETS AND LIABILITIES

I. CUSTOMER RELATIONSHIP INTANGIBLE ASSETS

Customer relationship intangible assets, which are acquired through either business combinations or acquisitions of customer relationships, are amortized over periods ranging from 10 to 30 years. Customer relationship intangible assets are recorded based upon estimates of their fair value.

II. CUSTOMER INDUCEMENTS

Payments that are made to a customer’s current records management vendor in order to terminate the customer’s existing contract with that vendor (“Permanent Withdrawal Fees”), or direct payments to a customer for which no distinct benefit is received in return, are collectively referred to as "Customer Inducements". Customer Inducements are treated as a reduction of the transaction price over periods ranging from one to 10 years and are included in storage and service revenue in the accompanying Consolidated Statements of Operations. If the customer terminates its relationship with us, the unamortized carrying value of the Customer Inducement intangible asset is charged to revenue. However, in the event of such termination, we generally collect, and record as income, permanent removal fees that generally equal or exceed the amount of the unamortized Customer Inducement intangible asset.

III. DATA CENTER INTANGIBLE ASSETS AND LIABILITIES

Finite-lived intangible assets associated with our Global Data Center Business consist of the following:

DATA CENTER IN-PLACE LEASE INTANGIBLE ASSETS AND DATA CENTER TENANT RELATIONSHIP INTANGIBLE ASSETS

Data Center In-Place Lease Intangible Assets (“Data Center In-Place Leases”) and Data Center Tenant Relationship Intangible Assets (“Data Center Tenant Relationships”) reflect the value associated with acquiring a data center operation with active tenants as of the date of acquisition. The value of Data Center In-Place Leases is determined based upon an estimate of the economic costs (such as lost revenues, tenant improvement costs, commissions, legal expenses and other costs to acquire new data center leases) avoided by acquiring a data center operation with active tenants that would have otherwise been incurred if the data center operation was purchased vacant. Data Center In-Place Leases are amortized over the weighted average remaining term of the acquired data center leases. The value of Data Center Tenant Relationships is determined based upon an estimate of the economic costs avoided upon lease renewal of the acquired tenants, based upon expectations of lease renewal. Data Center Tenant Relationships are amortized over the weighted average remaining anticipated life of the relationship with the acquired tenant.

DATA CENTER ABOVE-MARKET AND BELOW-MARKET IN-PLACE LEASE INTANGIBLE ASSETS

We record Data Center Above-Market In-Place Lease Intangible Assets (“Data Center Above-Market Leases”) and Data Center Below-Market In-Place Lease Intangible Assets (“Data Center Below-Market Leases”) at the net present value of the difference between (i) the contractual amounts to be paid pursuant to each in-place lease and (ii) management’s estimate of the fair market lease rates for each corresponding in-place lease. Data Center Above-Market Leases and Data Center Below-Market Leases are amortized over the remaining non-cancellable term of the acquired in-place lease to storage revenue.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

The gross carrying amount and accumulated amortization of our finite-lived intangible assets as of December 31, 2020 and 2019, respectively, are as follows:

	DECEMBER 31, 2020						DECEMBER 31, 2019
DESCRIPTION	GROSS CARRYING AMOUNT		ACCUMULATED AMORTIZATION		NET CARRYING AMOUNT		GROSS CARRYING AMOUNT		ACCUMULATED AMORTIZATION		NET CARRYING AMOUNT
Assets:
Customer relationship intangible assets(1)	$	1,852,700	$	(668,547)	$	1,184,153	$	1,751,848	$	(544,721)	$	1,207,127
Customer inducements(1)	49,098		(26,923)		22,175		52,718		(29,397)		23,321
Data center lease-based intangible assets(1)(2)	269,988		(149,339)		120,649		265,945		(103,210)		162,735
Third-party commissions asset(3)	34,317		(8,761)		25,556		31,708		(4,134)		27,574
Liabilities:
Data center below-market leases(4)	$	12,854	$	(5,943)	$	6,911	$	12,750	$	(3,937)	$	8,813

(1)Included in Customer relationships, customer inducements and data center lease-based intangibles in the accompanying Consolidated Balance Sheets as of December 31, 2020 and 2019.

(2)Data center lease-based intangible assets includes Data Center In-Place Leases, Data Center Tenant Relationships and Data Center Above-Market Leases.

(3)Included in Other (within Other Assets, Net) in the accompanying Consolidated Balance Sheets as of December 31, 2020 and 2019.

(4)Included in Other long-term liabilities in the accompanying Consolidated Balance Sheets as of December 31, 2020 and 2019.

Amortization expense associated with finite-lived intangible assets, revenue reduction associated with the amortization of Customer Inducements and net revenue reduction associated with the amortization of Data Center Above-Market Leases and Data Center Below-Market Leases for the years ended December 31, 2020, 2019 and 2018 is as follows:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Amortization expense included in depreciation and amortization associated with:
Customer relationship intangible assets	$	117,514	$	117,972	$	113,782
Data center in-place leases and tenant relationships	42,637		46,696		43,061
Third-party commissions asset and other finite-lived intangible assets	7,004		7,957		5,713
Revenue reduction associated with amortization of:
Customer inducements and data center above-market and below-market leases	$	9,878	$	13,703	$	16,281

Estimated amortization expense for existing finite-lived intangible assets (excluding Contract Fulfillment Costs, as defined and disclosed in Note 2.r.) is as follows:

	ESTIMATED AMORTIZATION
YEAR	INCLUDED IN DEPRECIATION AND AMORTIZATION		REVENUE REDUCTION ASSOCIATED WITH CUSTOMER INDUCEMENTS AND DATA CENTER ABOVE-MARKET AND BELOW-MARKET LEASES
2021	$	168,756	$	7,603
2022	139,983		5,010
2023	135,262		3,084
2024	130,298		1,453
2025	127,771		508
Thereafter	625,052		842

M. DEFERRED FINANCING COSTS

Deferred financing costs are amortized over the life of the related debt. If debt is retired early, the related unamortized deferred financing costs are written-off in the period the debt is retired to Other expense (income), net. See Note 6.

N. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

Every derivative instrument is required to be recorded in the balance sheet as either an asset or a liability measured at its fair value. Periodically, we acquire derivative instruments that are intended to hedge either cash flows or values that are subject to foreign exchange or other market price risk and not for trading purposes. We have formally documented our hedging relationships, including identification of the hedging instruments and the hedged items, as well as our risk management objectives and strategies for undertaking each hedge transaction. Given the recurring nature of our revenues and the long-term nature of our asset base, we have the ability and the preference to use long-term, fixed interest rate debt to finance our business, thereby preserving our long-term returns on invested capital. We may use interest rate swaps as a tool to maintain our targeted level of fixed rate debt. In addition, we may enter into cross-currency swaps to hedge the variability of exchange rates between the United States and our foreign subsidiaries, as well as interest rates. We may also use borrowings in foreign currencies, either obtained in the United States or by our foreign subsidiaries, to hedge foreign currency risk associated with our international investments. As of December 31, 2020 and 2019, none of our derivative instruments contained credit-risk related contingent features. See Note 5.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

O. FAIR VALUE MEASUREMENTS

Entities are permitted under GAAP to elect to measure certain financial instruments and certain other items at either fair value or cost. We have elected the cost measurement option in all circumstances where we had an option.

Our financial assets or liabilities that are carried at fair value are required to be measured using inputs from the three levels of the fair value hierarchy. A financial asset or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels of the fair value hierarchy are as follows:

Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access at the measurement date.

Level 2—Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs).

Level 3—Unobservable inputs that reflect our assumptions about the assumptions that market participants would use in pricing the asset or liability.

The assets and liabilities carried at fair value and measured on a recurring basis as of December 31, 2020 and 2019, respectively, are as follows:

			FAIR VALUE MEASUREMENTS AT DECEMBER 31, 2020 USING
DESCRIPTION	TOTAL CARRYING VALUE AT DECEMBER 31, 2020		QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1)			SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)			SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Money Market Funds(1)	$	62,657	$	—		$	62,657		$	—
Time Deposits(1)	2,121		—			2,121			—
Trading Securities	10,892		10,636		(2)	256		(3)	—
Derivative Liabilities(4)	49,703		—			49,703			—

			FAIR VALUE MEASUREMENTS AT DECEMBER 31, 2019 USING
DESCRIPTION	TOTAL CARRYING VALUE AT DECEMBER 31, 2019		QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1)			SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)			SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Money Market Funds(1)	$	13,653	$	—		$	13,653		$	—
Trading Securities	10,732		10,168		(2)	564		(3)	—
Derivative Liabilities(4)	9,756		—			9,756			—

(1)Money market funds and time deposits are measured based on quoted prices for similar assets and/or subsequent transactions.

(2)Certain trading securities are measured at fair value using quoted market prices.

(3)Certain trading securities are measured based on inputs other than quoted market prices that are observable.

(4)Derivative assets and liabilities include (i) interest rate swap agreements, including forward-starting interest rate swap agreements, to limit our exposure to changes in interest rates on a portion of our floating rate indebtedness and (ii) cross-currency swap agreements to hedge the variability of exchange rates impacts between the United States dollar and the Euro and certain of our Euro denominated subsidiaries. Our derivative financial instruments are measured using industry standard valuation models using market-based observable inputs, including interest rate curves, forward and spot prices for currencies and implied volatilities. Credit risk is also factored into the determination of the fair value of our derivative financial instruments. See Note 5 for additional information on our derivative financial instruments.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

We did not have any material items that are measured at fair value on a non-recurring basis for the years ended December 31, 2020, 2019, and 2018, with the exception of: (i) the reporting units as presented in our goodwill impairment analysis (as disclosed in Note 2.k.); (ii) the assets and liabilities acquired through acquisitions (as disclosed in Note 3); (iii) the redemption value of certain redeemable noncontrolling interests (as disclosed in Note 2.p.); and (iv) our initial investments in the Frankfurt JV, the MakeSpace JV and OSG (each as defined in Note 3), all of which are based on Level 3 inputs.

The fair value of our long-term debt, which was determined based on either Level 1 inputs or Level 3 inputs, is disclosed in Note 6. Long-term debt is measured at cost in our Consolidated Balance Sheets as of December 31, 2020 and 2019.

P. REDEEMABLE NONCONTROLLING INTERESTS

Certain unaffiliated third parties own noncontrolling interests in certain of our foreign consolidated subsidiaries. The underlying agreements between us and our noncontrolling interest shareholders for these subsidiaries contain provisions under which the noncontrolling interest shareholders can require us to purchase their respective interests in such subsidiaries at certain times and at a purchase price as stipulated in the underlying agreements (generally at fair value). These put options make these noncontrolling interests redeemable and, therefore, these noncontrolling interests are classified as temporary equity outside of stockholders’ equity. Redeemable noncontrolling interests are reported at the higher of their redemption value or the noncontrolling interest holders’ proportionate share of the underlying subsidiaries net carrying value. Increases or decreases in the redemption value of the noncontrolling interest are offset against Additional Paid-in Capital.

In 2018, one of our noncontrolling interest shareholders exercised its option to put its ownership interest back to us. Upon the exercise of the put option, this noncontrolling interest became mandatorily redeemable by us, and, therefore, is accounted for as a liability rather than a component of redeemable noncontrolling interests. Subject to agreement on final settlement terms and conditions, we and this noncontrolling interest shareholder have agreed in principle on the put option price for the noncontrolling interest shares. We are in dispute with this noncontrolling interest shareholder with respect to whether interest from the date of the put and certain other costs should be reimbursable to the noncontrolling interest shareholder. We intend to vigorously defend that interest and certain other reimbursable costs are not owed to the noncontrolling interest shareholder. We have recorded our estimate of the fair value of these noncontrolling interest shares as a component of Accrued expenses on our Consolidated Balance Sheets as of December 31, 2020 and 2019. It is possible that the value ultimately agreed upon with the noncontrolling interest shareholder could differ from our current estimate of the fair value. Subsequent to these noncontrolling interest shares becoming mandatorily redeemable, any increase or decrease in the fair value of such noncontrolling interest is included as a component of Other expense (income), net on our Consolidated Statements of Operations.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

Q. ACCUMULATED OTHER COMPREHENSIVE ITEMS, NET

The changes in accumulated other comprehensive items, net for the years ended December 31, 2020, 2019 and 2018 are as follows:

	FOREIGN CURRENCY  TRANSLATION AND OTHER ADJUSTMENTS		CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS		TOTAL
Balance as of December 31, 2017	$	(103,989)	$	—	$	(103,989)
Other comprehensive (loss) income:
Foreign currency translation and other adjustments	(160,702)		—		(160,702)
Change in fair value of derivative instruments	—		(973)		(973)
Total other comprehensive (loss) income	(160,702)		(973)		(161,675)
Balance as of December 31, 2018	(264,691)		(973)		(265,664)
Other comprehensive income (loss):
Foreign currency translation and other adjustments	11,866		—		11,866
Change in fair value of derivative instruments	—		(8,783)		(8,783)
Total other comprehensive income (loss)	11,866		(8,783)		3,083
Balance as of December 31, 2019	(252,825)		(9,756)		(262,581)
Other comprehensive income (loss):
Foreign currency translation and other adjustments	46,635		—		46,635
Change in fair value of derivative instruments	—		(39,947)		(39,947)
Total other comprehensive income (loss)	46,635		(39,947)		6,688
Balance as of December 31, 2020	$	(206,190)	$	(49,703)	$	(255,893)

R. REVENUES

Our revenues consist of storage rental revenues as well as service revenues and are reflected net of sales and value-added taxes. Storage rental revenues, which are considered a key driver of financial performance for the storage and information management services industry, consist primarily of recurring periodic rental charges related to the storage of materials or data (generally on a per unit basis) that are typically retained by customers for many years and revenues associated with our data center operations. Service revenues include charges for related service activities, the most significant of which include: (1) the handling of records, including the addition of new records, temporary removal of records from storage, refiling of removed records, customer termination and permanent removal fees, project revenues and courier operations, consisting primarily of the pickup and delivery of records upon customer request; (2) destruction services, consisting primarily of secure shredding of sensitive documents and the subsequent sale of shredded paper for recycling, the price of which can fluctuate from period to period; and (3) digital solutions including scanning, imaging and document conversion services of active and inactive records, and consulting services.

We account for revenue in accordance with ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”). Customers are generally billed monthly based on contractually agreed-upon terms, and storage rental and service revenues are recognized in the month the respective storage rental or service is provided, in line with the transfer of control to the customer. When storage rental fees or services are billed in advance, amounts related to future storage rental or prepaid service contracts are accounted for as deferred revenue and recognized upon the transfer of control to the customer, generally ratably over the contract term. Customer contracts generally include promises to provide monthly recurring storage and related services that are essentially the same over time and have the same pattern of transfer of control to the customer; therefore, most performance obligations represent a promise to deliver a series of distinct services over time (as determined for purposes of ASU 2014-09, a “series”). For those contracts that qualify as a series, we have a right to consideration from the customer in an amount that corresponds directly with the value of the underlying performance obligation transferred to the customer to date. This concept is known as "right to invoice” and we apply the “right to invoice” practical expedient to all revenues, with the exception of storage revenues in our Global Data Center Business (which are subject to leasing guidance). Additionally, each purchasing decision is fully in the control of the customer and; therefore, consideration beyond the current reporting period is variable and allocated to the specific period to which the consideration relates, which is consistent with the practical expedient.

Our Global Data Center Business features storage rental provided to the customer at contractually specified rates over a fixed contractual period. Storage rental revenue related to the storage component of our Global Data Center Business is recognized on a straight-line basis over the contract term in accordance with ASU 2016-02. The revenue related to the service component of our Global Data Center Business is recognized in the period the related services are provided.

The costs associated with the initial movement of customer records into physical storage and certain commissions are considered costs to obtain or fulfill customer contracts (“Contract Fulfillment Costs”). The following describes each of these Contract Fulfillment Costs recognized under ASU 2014-09:

INTAKE COSTS (AND ASSOCIATED DEFERRED REVENUE)

The costs of the initial intake of customer records into physical storage (“Intake Costs”) are deferred and amortized as a component of depreciation and amortization in our Consolidated Statements of Operations over three years, consistent with the transfer of the performance obligation to the customer to which the asset relates. In instances where such Intake Costs are billed to the customer, the associated revenue is deferred and recognized over the same three-year period.

COMMISSIONS

Certain commission payments that are directly associated with the fulfillment of long-term storage contracts are capitalized and amortized as a component of depreciation and amortization in our Consolidated Statements of Operations over three years, consistent with the transfer of the performance obligation to the customer to which the asset relates. Certain direct commission payments associated with contracts with a duration of one year or less are expensed as incurred under the practical expedient which allows an entity to expense as incurred an incremental cost of obtaining a contract if the amortization period of the asset that the entity otherwise would have recognized is one year or less.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

Contract Fulfillment Costs, which are included as a component of Other within Other Assets, Net, as of December 31, 2020 and 2019 are as follows:

	DECEMBER 31, 2020						DECEMBER 31, 2019
DESCRIPTION	GROSS CARRYING AMOUNT		ACCUMULATED AMORTIZATION		NET CARRYING AMOUNT		GROSS CARRYING AMOUNT		ACCUMULATED AMORTIZATION		NET CARRY ING AMOUNT
Intake Costs asset	$	63,721	$	(33,352)	$	30,369	$	41,224	$	(23,579)	$	17,645
Commissions asset	91,069		(38,787)		52,282		68,008		(27,178)		40,830

Amortization expense associated with the Intake Costs and Commissions assets for the years ended December 31, 2020, 2019 and 2018 are as follows:

	YEAR ENDED DECEMBER 31,
DESCRIPTION	2020		2019		2018
Intake Costs asset	$	13,300	$	10,144	$	10,380
Commissions asset	24,052		19,109		13,838

Estimated amortization expense for Contract Fulfillment Costs is as follows:

YEAR	ESTIMATED AMORTIZATION
2021	$	38,954
2022	24,861
2023	18,836

Deferred revenue liabilities are reflected as follows in our Consolidated Balance Sheets:

		DECEMBER 31,
DESCRIPTION	LOCATION IN BALANCE SHEET	2020		2019
Deferred revenue - Current	Deferred revenue	$	295,785	$	274,036
Deferred revenue - Long-term	Other Long-term Liabilities	35,612		36,029

DATA CENTER LESSOR CONSIDERATIONS

Our Global Data Center Business features storage rental provided to customers at contractually specified rates over a fixed contractual period. Prior to January 1, 2019, our data center revenue contracts were accounted for in accordance with ASC 840. Beginning on January 1, 2019, our data center revenue contracts are accounted for in accordance with ASU 2016-02. ASU 2016-02 provides a practical expedient which allows lessors to account for nonlease components (such as power and connectivity, in the case of our Global Data Center Business) with the related lease component if both the timing and pattern of transfer are the same for nonlease components and the lease component, and the lease component, if accounted for separately, would be classified as an operating lease. The single combined component is accounted for under ASU 2016-02 if the lease component is the predominant component and is accounted for under ASU 2014-09 if the nonlease components are the predominant components. We have elected to take this practical expedient.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

Storage rental revenue, including revenue associated with power and connectivity, associated with our Global Data Center Business for the years ended December 31, 2020, 2019 and 2018 are as follows:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Storage rental revenue(1)	$	263,695	$	246,925	$	218,675

(1)Revenue associated with power and connectivity included within storage rental revenue was $47,451, $43,269 and $38,749 for the years ended December 31, 2020, 2019 and 2018, respectively.

The revenue related to the service component of our Global Data Center Business remains unchanged from the adoption of ASU 2016-02 and is recognized in the period the related services are provided. Our accounting treatment for data center revenue was not significantly impacted by the adoption of ASU 2016-02.

The future minimum lease payments we expect to receive under non-cancellable data center operating leases for which we are the lessor, excluding month to month leases, for the next five years are as follows:

YEAR	FUTURE MINIMUM LEASE PAYMENTS
2021	$	225,554
2022	183,027
2023	142,787
2024	111,106
2025	77,308

STOCK-BASED COMPENSATION

We record stock-based compensation expense, utilizing the straight-line method, for the cost of stock options, restricted stock units (“RSUs”), performance units (“PUs”) and shares of stock issued under our employee stock purchase plan (“ESPP”) (together, "Employee Stock-Based Awards”).

For our Employee Stock-Based Awards made on or after February 20, 2019, we have included the following retirement provision:

•Upon an employee’s retirement on or after attaining age 58, if the sum of (i) the award recipient’s age at retirement and (ii) the award recipient’s years of service with the company totals at least 70, the award recipient is entitled to continued vesting of any outstanding Employee Stock-Based Awards which include the 2019 Retirement Criteria subsequent to their retirement, provided that, for awards granted in the year of retirement, their retirement occurs on or after July 1 (the “2019 Retirement Criteria”).

•Accordingly, (i) grants of Employee Stock-Based Awards to an employee who has met the 2019 Retirement Criteria on or before the date of grant, or will meet the Retirement Criteria before July 1 of the year of the grant, will be expensed between the date of grant and July 1 of the grant year and (ii) grants of Employee Stock-Based Awards to employees who will meet the 2019 Retirement Criteria during the award’s normal vesting period will be expensed between the date of grant and the date upon which the award recipient meets the 2019 Retirement Criteria.

•Stock options and RSUs granted to recipients who meet the 2019 Retirement Criteria will continue vesting on the original vesting schedule. If an employee retires and has met the 2019 Retirement Criteria, stock options will remain exercisable for up to three years or the original expiration date of the stock options, if earlier. PUs granted to recipients who meet the 2019 Retirement Criteria will continue to vest and be delivered in accordance with the original vesting schedule of the applicable PU award and remain subject to the same performance conditions.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

Stock-based compensation expense for Employee Stock-Based Awards included in the accompanying Consolidated Statements of Operations for the years ended December 31, 2020, 2019 and 2018 is as follows:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Stock-based compensation expense	$	37,674	$	35,654	$	31,167
Stock-based compensation expense, after tax	36,584		33,103		28,998

The substantial majority of stock-based compensation expense for Employee Stock-Based Awards is included in Selling, general and administrative expenses in the accompanying Consolidated Statements of Operations.

STOCK OPTIONS

Options are generally granted with exercise prices equal to the market price of the stock on the date of grant; however, in certain instances, options are granted at prices greater than the market price of the stock on the date of grant. The substantial majority of options we issue become exercisable ratably over a period three years from the date of grant and have a contractual life of 10 years from the date of grant, unless the holder’s employment is terminated sooner. Our non-employee directors are considered employees for purposes of our stock option plans and stock option reporting.

The substantial majority of the stock options outstanding at December 31, 2020 are based on the three-year vesting period (10 year contractual life) described above.

Our equity compensation plans generally provide that, upon a vesting change in control (as defined in each plan), any unvested options and other awards granted thereunder shall vest immediately if an employee is terminated as a result of the change in control or terminates their own employment for good reason (as defined in each plan). On January 20, 2015, our stockholders approved the adoption of the Iron Mountain Incorporated 2014 Stock and Cash Incentive Plan, as amended (the "2014 Plan”). Under the 2014 Plan, the total amount of shares of common stock reserved and available for issuance pursuant to awards granted under the 2014 Plan is 12,750,000. The 2014 Plan permits us to continue to grant awards through May 24, 2027.

A total of 48,253,839 shares of common stock have been reserved for grants of options and other rights under our various stock incentive plans, including the 2014 Plan. The number of shares available for grant under our various stock incentive plans, not including the ESPP, at December 31, 2020 was 2,818,706.

The weighted average fair value of stock options granted in 2020, 2019 and 2018 was $2.35, $3.58 and $3.50 per share, respectively. These values were estimated on the date of grant using the Black-Scholes option pricing model. The weighted average assumptions used for grants in the years ended December 31, 2020, 2019 and 2018 are as follows:

	YEAR ENDED DECEMBER 31,
WEIGHTED AVERAGE ASSUMPTIONS	2020		2019		2018
Expected volatility(1)	25.4	%	24.3	%	25.4	%
Risk-free interest rate(2)	1.45	%	2.47	%	2.65	%
Expected dividend yield(3)	7	%	7	%	7	%
Expected life(4)	10.0 years		5.0 years		5.0 years

(1)Expected volatility is calculated utilizing daily historical volatility over a period that equates to the expected life of the option.

(2)Risk-free interest rate is based on the United States Treasury interest rates whose term is consistent with the expected life (estimated period of time outstanding) of the stock options.

(3)Expected dividend yield is considered in the option pricing model and represents our current annualized expected per share dividends over the current trade price of our common stock.

(4)Expected life of the stock options granted is estimated using the historical exercise behavior of employees.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

A summary of stock option activity for the year ended December 31, 2020 is as follows:

	OPTIONS	WEIGHTED AVERAGE EXERCISE PRICE		WEIGHTED AVERAGE REMAINING CONTRACTUAL TERM (YEARS)	AGGREGATE INTRINSIC VALUE
Outstanding at December 31, 2019	4,835,721	$	35.64
Granted	589,993	33.32
Exercised	(204,540)	24.38
Forfeited	(151,230)	35.36
Expired	(337,425)	35.82
Outstanding at December 31, 2020	4,732,519	$	35.83	6.27	$	469
Options exercisable at December 31, 2020	3,439,748	$	36.40	5.46	$	469
Options expected to vest	1,266,640	$	34.28	8.41	$	—

RESTRICTED STOCK UNITS

Our RSUs generally have a vesting period of three years from the date of grant. However, RSUs granted to our non-employee directors vest immediately upon grant. All RSUs accrue dividend equivalents associated with the underlying stock as we declare dividends. Dividends will generally be paid to holders of RSUs in cash upon the vesting date of the associated RSU and will be forfeited if the RSU does not vest. The fair value of RSUs is the excess of the market price of our common stock at the date of grant over the purchase price (which is typically zero).

The fair value of RSUs vested during the years ended December 31, 2020, 2019 and 2018, are as follows:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Fair value of RSUs vested	$	26,492	$	21,191	$	20,454

A summary of RSU activity for the year ended December 31, 2020 is as follows:

	RSUs	WEIGHTED-AVERAGE GRANT-DATE FAIR VALUE
Non-vested at December 31, 2019	1,203,599	$	34.71
Granted	1,078,124	31.68
Vested	(792,083)	33.45
Forfeited	(195,634)	34.28
Non-vested at December 31, 2020	1,294,006	$	33.02

PERFORMANCE UNITS

The PUs we issue vest based on our performance against predefined operational and share based targets. PUs granted in 2018 vest based on targets for revenue, Adjusted EBITDA, and total return on our common stock in relation to the MSCI United States REIT Index ("TSR Target") and the number of PUs earned may range from 0% to 200% of the initial award. For awards granted in 2019 and thereafter, the vesting is subject to a minimum level of return on invested capital (“ROIC”) in the third year of the performance period, and thereafter the number of PUs earned is based on (i) the revenue performance for each year averaged at the end of the three-year performance period, (ii) the revenue exit rate of new products in the last quarter of the three-year performance period and (iii) a TSR Target. With respect to the PUs granted in 2019 and thereafter, the number of PUs earned may range from 0% to 219% of the initial award.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

All of our PUs will be settled in shares of our common stock and are subject to cliff vesting three years from the date of the original PU grant. As detailed above, PUs granted:

•On or after February 20, 2019, are subject to the 2019 Retirement Criteria. PUs granted to recipients who meet the 2019 Retirement Criteria will continue to vest and be delivered in accordance with the original vesting schedule of the applicable PU award and remain subject to the same performance conditions.

•Prior to February 20, 2019, employees who terminate their employment during the three-year performance period and on or after attaining age 55 and completing 10 years of qualifying service are eligible for pro-rated vesting, subject to the actual achievement against the predefined targets or a market condition as discussed above, based on the number of full years of service completed following the grant date (but delivery of the shares remains deferred).

As a result, PUs are generally expensed over the three-year performance period.

All PUs accrue dividend equivalents associated with the underlying stock as we declare dividends. Dividends will generally be paid to holders of PUs in cash upon the settlement date of the associated PU and will be forfeited if the PU does not vest.

During the years ended December 31, 2020, 2019 and 2018, we issued 425,777, 380,856 and 353,507 PUs, respectively. We forecast the likelihood of achieving the predefined targets for our PUs in order to calculate the expected PUs to be earned. We record a compensation charge based on either the forecasted PUs to be earned (during the performance period) or the actual PUs earned (at the three-year anniversary of the grant date) over the vesting period for each of the awards. The fair value of PUs based on our performance against predefined targets is the excess of the market price of our common stock at the date of grant over the purchase price (which is typically zero). For PUs earned based on a market condition, we utilize a Monte Carlo simulation to fair value these awards at the date of grant, and such fair value is expensed over the three-year performance period. As of December 31, 2020, we expected 100%, 100% and 0% achievement of the predefined targets associated with the awards of PUs made in 2020, 2019 and 2018, respectively.

The fair value of earned PUs that vested during the years ended December 31, 2020, 2019 and 2018, is as follows:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Fair value of earned PUs that vested	$	11,812	$	6,503	$	3,117

A summary of PU activity for the year ended December 31, 2020 is as follows:

	ORIGINAL PU AWARDS	PU ADJUSTMENT(1)	TOTAL PU AWARDS	WEIGHTED-AVERAGE GRANT-DATE FAIR VALUE
Non-vested at December 31, 2019	1,113,691	(314,798)	798,893	$	36.56
Granted	425,777	—	425,777	34.85
Vested	(316,730)	—	(316,730)	37.29
Forfeited/Performance or Market Conditions Not Achieved	(149,529)	(4,710)	(154,239)	28.28
Non-vested at December 31, 2020	1,073,209	(319,508)	753,701	$	36.98

(1)Represents an increase or decrease in the number of original PUs awarded based on either the final performance criteria or market condition achievement at the end of the performance period of such PUs or a change in estimated awards based on the forecasted performance against the predefined targets.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

EMPLOYEE STOCK PURCHASE PLAN

We offer an ESPP in which participation is available to substantially all United States and Canadian employees who meet certain service eligibility requirements. The ESPP provides for the purchase of our common stock by eligible employees through successive offering periods. We have historically had two six-month offering periods per year, the first of which generally runs from June 1 through November 30 and the second of which generally runs from December 1 through May 31. During each offering period, participating employees accumulate after-tax payroll contributions, up to a maximum of 15% of their compensation, to pay the purchase price at the end of the offering. Participating employees may withdraw from an offering before the purchase date and obtain a refund of the amounts withheld as payroll deductions. At the end of the offering period, outstanding options under the ESPP are exercised, and each employee’s accumulated contributions are used to purchase our common stock. The price for shares purchased under the ESPP is 95% of the fair market price at the end of the offering period, without a look-back feature. As a result, we do not recognize compensation expense for the ESPP shares purchased. For the years ended December 31, 2020, 2019 and 2018, there were 159,853, 129,505 and 119,123 shares, respectively, purchased under the ESPP. As of December 31, 2020, we have 216,287 shares available under the ESPP.

________________________________________________________

As of December 31, 2020, unrecognized compensation cost related to the unvested portion of our Employee Stock-Based Awards was $39,056 and is expected to be recognized over a weighted-average period of 1.7 years.

We issue shares of our common stock for the exercises of stock options, and the vesting of RSUs, PUs and shares of our common stock under our ESPP from unissued reserved shares.

T. OTHER EXPENSE (INCOME), NET

Consolidated other expense (income), net for the years ended December 31, 2020, 2019 and 2018 consists of the following:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Foreign currency transaction losses (gains), net(1)	$	29,830	$	24,852	$	(15,567)
Debt extinguishment expense	68,300		—		—
Other, net(2)	45,415		9,046		3,875
Other Expense (Income), Net	$	143,545	$	33,898	$	(11,692)

(1)The gain or loss on foreign currency transactions, calculated as the difference between the historical exchange rate and the exchange rate at the applicable measurement date, includes gains or losses primarily related to (i) borrowings in certain foreign currencies under our Revolving Credit Facility (as defined in Note 6), (ii) our previously outstanding Euro Notes (as defined in Note 6), (iii) certain foreign currency denominated intercompany obligations of our foreign subsidiaries to us and between our foreign subsidiaries, which are not considered permanently invested and (iv) amounts that are paid or received on the net settlement amount from forward contracts (as more fully discussed in Note 5).

(2)Other, net for the year ended December 31, 2020 consists primarily of changes in the estimated value of our mandatorily redeemable noncontrolling interests as well as losses on our equity method investments.

U. INCOME TAXES

Accounting for income taxes requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the tax and financial reporting bases of assets and liabilities and for loss and credit carryforwards. Valuation allowances are provided when recovery of deferred tax assets does not meet the more likely than not standard as defined in GAAP. We have elected to recognize interest and penalties associated with uncertain tax positions as a component of the Provision (benefit) for income taxes in the accompanying Consolidated Statements of Operations.

V. INCOME (LOSS) PER SHARE—BASIC AND DILUTED

Basic income (loss) per common share is calculated by dividing income (loss) by the weighted average number of common shares outstanding. The calculation of diluted income (loss) per share is consistent with that of basic income (loss) per share but gives effect to all potential common shares (that is, securities such as stock options, RSUs, PUs, warrants or convertible securities) that were outstanding during the period, unless the effect is antidilutive.

The calculation of basic and diluted income (loss) per share for the years ended December 31, 2020, 2019 and 2018 is as follows:

	YEAR ENDED DECEMBER 31,
	2020		2019		2018
Income (loss) from continuing operations	$	343,096	$	268,211	$	367,558
Less: Net income (loss) attributable to noncontrolling interests	403		938		1,198
Income (loss) from continuing operations (utilized in numerator of Earnings Per Share calculation)	342,693		267,273		366,360
Income (loss) from discontinued operations, net of tax	—		104		(12,427)
Net income (loss) attributable to Iron Mountain Incorporated	$	342,693	$	267,377	$	353,933
Weighted-average shares—basic	288,183,000		286,971,000		285,913,000
Effect of dilutive potential stock options	24,903		145,509		234,558
Effect of dilutive potential RSUs and PUs	435,287		570,435		505,030
Weighted-average shares—diluted	288,643,190		287,686,944		286,652,588
Earnings (losses) per share—basic:
Income (loss) from continuing operations	$	1.19	$	0.93	$	1.28
(Loss) income from discontinued operations, net of tax	—		—		(0.04)
Net income (loss) attributable to Iron Mountain Incorporated(1)	$	1.19	$	0.93	$	1.24
Earnings (losses) per share—diluted:
Income (loss) from continuing operations	$	1.19	$	0.93	$	1.28
(Loss) income from discontinued operations, net of tax	—		—		(0.04)
Net income (loss) attributable to Iron Mountain Incorporated(1)	$	1.19	$	0.93	$	1.23
Antidilutive stock options, RSUs and PUs, excluded from the calculation	5,663,981		4,475,745		3,258,078

(1)Columns may not foot due to rounding.

W. NEW ACCOUNTING PRONOUNCEMENTS

RECENTLY ADOPTED ACCOUNTING PRONOUNCEMENTS

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which makes a number of changes meant to add, modify or remove certain disclosure requirements associated with the movement of our financial assets and liabilities among the three levels of the fair value hierarchy. We adopted ASU 2018-13 on January 1, 2020. ASU 2018-13 did not have a material impact on our consolidated financial statements.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)

OTHER AS YET ADOPTED ACCOUNTING PRONOUNCEMENTS

In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) (“ASU 2020-04”). ASU 2020-04 provides optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions, for a limited period of time, to ease the potential burden of recognizing the effects of reference rate reform on financial reporting. The amendments in ASU 2020-04 apply to contracts, hedging relationships and other transactions that reference the London Inter-Bank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued due to the global transition away from LIBOR and certain other interbank offered rates. An entity may elect to apply the amendments provided by ASU 2020-04 beginning March 12, 2020 through December 31, 2022. We are currently evaluating these amendments as they relate to our contracts, hedging relationships and other transactions that reference LIBOR, as well as the impact of ASU 2020-04 on our consolidated financial statements.

In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740) (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions for recognizing deferred taxes for investments, performing intra-period allocation and calculating income taxes in interim periods. ASU 2019-12 also adds guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. ASU 2019-12 is effective for us on January 1, 2021. We do not expect that ASU 2019-12 will have a material impact on our consolidated financial statements