Investments in Real Estate (Schedule of Real Estate Property Acquisitions) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Real Estate Properties [Line Items]
Land	$ 1,136,341	$ 746,822
Acquired Ground Lease	11,150	11,335
Building and Improvements	15,215,405	10,267,525
Tenant Improvements	553,040	532,787
Accumulated Depreciation and Amortization	(3,238,227)	(2,668,509)
Net investments in properties	13,677,709	8,889,960
Direct and accrued costs related to work in progress	1,400,000	700,000
Internet Gateway Data Centers
Real Estate Properties [Line Items]
Land	109,844	109,083
Acquired Ground Lease	0	0
Building and Improvements	1,940,495	1,834,052
Tenant Improvements	99,174	93,472
Accumulated Depreciation and Amortization	(778,659)	(674,823)
Net investments in properties	1,370,854	1,361,784
Data Centers
Real Estate Properties [Line Items]
Land	1,010,306	610,007
Acquired Ground Lease	11,150	10,014
Building and Improvements	13,147,042	8,254,108
Tenant Improvements	453,712	431,444
Accumulated Depreciation and Amortization	(2,430,984)	(1,932,127)
Net investments in properties	12,191,226	7,373,446
Technology Manufacturing
Real Estate Properties [Line Items]
Land	11,959	20,199
Acquired Ground Lease	0	1,321
Building and Improvements	1,564	57,765
Tenant Improvements	76	6,333
Accumulated Depreciation and Amortization	(31)	(24,595)
Net investments in properties	13,568	61,023
Technology Office
Real Estate Properties [Line Items]
Land	2,067	5,368
Acquired Ground Lease	0	0
Building and Improvements	23,029	43,574
Tenant Improvements	0	1,460
Accumulated Depreciation and Amortization	(16,779)	(21,407)
Net investments in properties	8,317	28,995
Other
Real Estate Properties [Line Items]
Land	2,165	2,165
Acquired Ground Lease	0	0
Building and Improvements	103,275	78,026
Tenant Improvements	78	78
Accumulated Depreciation and Amortization	(11,774)	(15,557)
Net investments in properties	$ 93,744	$ 64,712