Acquisitions (Narrative) (Details) $ in Thousands			9 Months Ended
	Jun. 06, 2016 USD ($) ft² a MW	Jun. 16, 2015 USD ($) property customer	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Mar. 23, 2015 USD ($)	Jul. 23, 2014 USD ($)
Business Acquisition [Line Items]
Cash consideration paid for acquisition			$ 197,751	$ 252,156
Piscataway Facility [Member]
Business Acquisition [Line Items]
Date of acquisition			Jun. 06, 2016
Acquisition costs	$ 125,800
Amoritization of intangible assets in the remainder of the year			$ 3,000
Amoritization of intangible assets in 2017			4,000
Amoritization of intangible assets in 2018			2,900
Amoritization of intangible assets in 2019			2,300
Amoritization of intangible assets in 2020			1,700
Acres of real estate property | a	38
Area of facility (in square feet) | ft²	360,000
Piscataway Facility [Member] | Offsets To Rental Revenue [Member] | Above And Below Market Leases [Member]
Business Acquisition [Line Items]
Amoritization of intangible assets in the remainder of the year			900
Amoritization of intangible assets in 2017			1,100
Amoritization of intangible assets in 2018			700
Amoritization of intangible assets in 2019			500
Amoritization of intangible assets in 2020			600
Piscataway Facility [Member] | Raised Floor With 18 MW of Critical Power [Member]
Business Acquisition [Line Items]
Area of facility (in square feet) | ft²	89,000
Capacity of the plant (in MW) | MW	18
Piscataway Facility [Member] | Additional Raised Floor With 8 MW of Additional Critical Power [Member]
Business Acquisition [Line Items]
Area of facility (in square feet) | ft²	87,000
Capacity of the plant (in MW) | MW	8
Carpathia Hosting, Inc. [Member]
Business Acquisition [Line Items]
Acquisition costs		$ 373,600
Number of customers of acquired entity | customer		230
Number of domestic data centers acquired | property		8
Number of international data centers acquired | property		5
Tax basis of deductible amount of goodwill acquired		$ 16,600
Amoritization of intangible assets in the remainder of the year			12,200
Amoritization of intangible assets in 2017			12,200
Amoritization of intangible assets in 2018			10,100
Amoritization of intangible assets in 2019			8,000
Amoritization of intangible assets in 2020			$ 8,000
Senior Notes [Member]
Business Acquisition [Line Items]
Notes issued					$ 300,000	$ 300,000
Carpathia Hosting, Inc. [Member]
Business Acquisition [Line Items]
Ownership interest			87.60%
Equity Method Investment Ownership Percentage			87.60%
Carpathia Hosting, Inc. [Member] | Carpathia Hosting, Inc. [Member]
Business Acquisition [Line Items]
Ownership interest		100.00%