Acquisitions (Narrative) (Details) $ in Thousands				12 Months Ended
	Dec. 16, 2016 USD ($) MW	Jun. 06, 2016 USD ($) ft² a MW	Jun. 16, 2015 USD ($) property customer	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 16, 2016 ft²	Dec. 16, 2016 a	Mar. 23, 2015 USD ($)	Jul. 23, 2014 USD ($)
Business Acquisition [Line Items]
Number of customers of acquired entity | customer			230
Number of domestic data centers acquired | property			8
Number of international data centers acquired | property			5
Cash consideration paid for acquisition				$ 279,905	$ 320,058	$ 201,145
Above Market Leases
Business Acquisition [Line Items]
Amortization of intangible assets in 2017				200
Amortization of intangible assets in 2018				200
Amortization of intangible assets in 2019				200
Amortization of intangible assets in 2020				200
Amortization of intangible assets in 2021				200
Fort Worth Facility
Business Acquisition [Line Items]
Acquisition costs	$ 50,100
Area of facility (in square feet)							262,000	53
Fort Worth Facility | Raised Floor With 18 MW of Critical Power
Business Acquisition [Line Items]
Area of facility (in square feet) | ft²							80,000
Fort Worth Facility | Additional Raised Floor With 8 MW of Additional Critical Power
Business Acquisition [Line Items]
Capacity of the plant (in MW) | MW	8
Piscataway Facility
Business Acquisition [Line Items]
Acquisition costs		$ 125,800
Amortization of intangible assets in 2017		4,000
Amortization of intangible assets in 2018		2,900
Amortization of intangible assets in 2019		2,300
Amortization of intangible assets in 2020		1,700
Amortization of intangible assets in 2021		$ 500
Acres of real estate property | a		38
Area of facility (in square feet) | ft²		360,000
Piscataway Facility | Offsets To Rental Revenue [Member] | Above And Below Market Leases [Member]
Business Acquisition [Line Items]
Amortization of intangible assets in 2017		$ 1,100
Amortization of intangible assets in 2018		700
Amortization of intangible assets in 2019		500
Amortization of intangible assets in 2020		600
Amortization of intangible assets in 2021		$ 0
Piscataway Facility | Raised Floor With 18 MW of Critical Power
Business Acquisition [Line Items]
Area of facility (in square feet) | ft²		89,000
Capacity of the plant (in MW) | MW		18
Piscataway Facility | Additional Raised Floor With 8 MW of Additional Critical Power
Business Acquisition [Line Items]
Area of facility (in square feet) | ft²		87,000
Capacity of the plant (in MW) | MW		8
Carpathia Hosting, Inc.
Business Acquisition [Line Items]
Acquisition costs			$ 373,600
Tax basis of deductible amount of goodwill acquired			$ 16,600
Amortization of intangible assets in 2017				12,200
Amortization of intangible assets in 2018				9,900
Amortization of intangible assets in 2019				8,000
Amortization of intangible assets in 2020				8,000
Amortization of intangible assets in 2021				$ 8,000
Senior Notes [Member]
Business Acquisition [Line Items]
Notes issued									$ 300,000	$ 300,000
Carpathia Hosting, Inc. | Carpathia Hosting, Inc.
Business Acquisition [Line Items]
Ownership interest			100.00%