Investments In Real Estate (Summary of Investment Properties) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Real Estate Properties [Line Items]
Land	$ 689,573	$ 671,602
Acquired Ground Lease	12,639	12,196
Building and Improvements	9,676,427	8,823,814
Tenant Improvements	536,734	475,000
Accumulated Depreciation and Amortization	(2,251,268)	(1,874,054)
Net investments in properties	8,664,105	8,108,558
Direct and accrued costs related to work in progress	700,000	800,000
Internet Gateway Data Centers
Real Estate Properties [Line Items]
Land	109,389	112,265
Acquired Ground Lease	0	0
Building and Improvements	1,441,749	1,459,930
Tenant Improvements	95,185	99,864
Accumulated Depreciation and Amortization	(608,153)	(541,023)
Net investments in properties	1,038,170	1,131,036
Corporate Data Centers
Real Estate Properties [Line Items]
Land	551,372	525,192
Acquired Ground Lease	11,317	12,196
Building and Improvements	8,055,059	7,117,789
Tenant Improvements	433,682	368,837
Accumulated Depreciation and Amortization	(1,586,509)	(1,286,024)
Net investments in properties	7,464,921	6,737,990
Technology Manufacturing
Real Estate Properties [Line Items]
Land	20,199	25,471
Acquired Ground Lease	1,322	0
Building and Improvements	56,254	67,238
Tenant Improvements	6,333	4,764
Accumulated Depreciation and Amortization	(22,677)	(20,506)
Net investments in properties	61,431	76,967
Technology Office
Real Estate Properties [Line Items]
Land	5,368	5,368
Acquired Ground Lease	0	0
Building and Improvements	43,154	42,356
Tenant Improvements	1,459	1,459
Accumulated Depreciation and Amortization	(18,564)	(14,759)
Net investments in properties	31,417	34,424
Other
Real Estate Properties [Line Items]
Land	3,245	3,306
Acquired Ground Lease	0	0
Building and Improvements	80,211	136,501
Tenant Improvements	75	76
Accumulated Depreciation and Amortization	(15,365)	(11,742)
Net investments in properties	$ 68,166	$ 128,141