Real Estate Assets and Construction in Progress (Summary of Owned or Leased Properties by the Company) (Details) $ in Thousands	Dec. 31, 2019 USD ($) property	Dec. 31, 2018 USD ($) property
Real Estate Properties [Line Items]
Land	$ 130,605	$ 105,541
Buildings, Improvements and Equipment	2,178,901	1,917,251
Construction in progress	920,922	790,064
Total cost	3,230,428	2,812,856
Manassas, Virginia | Assets Held For Sale
Real Estate Properties [Line Items]
Construction in progress	71,000
Owned Properties | Atlanta, Georgia Campus
Real Estate Properties [Line Items]
Land	44,588	20,416
Buildings, Improvements and Equipment	525,300	493,446
Construction in progress	128,930	88,253
Total cost	698,818	602,115
Owned Properties | Irving, Texas
Real Estate Properties [Line Items]
Land	8,606	8,606
Buildings, Improvements and Equipment	369,727	345,615
Construction in progress	98,170	99,445
Total cost	476,503	453,666
Owned Properties | Richmond, Virginia
Real Estate Properties [Line Items]
Land	2,180	2,180
Buildings, Improvements and Equipment	195,684	253,098
Construction in progress	139,948	67,932
Total cost	337,812	323,210
Owned Properties | Chicago, Illinois
Real Estate Properties [Line Items]
Land	9,400	9,400
Buildings, Improvements and Equipment	205,026	130,150
Construction in progress	86,878	133,095
Total cost	301,304	272,645
Owned Properties | Ashburn, Virginia
Real Estate Properties [Line Items]
Land	16,476	17,325
Buildings, Improvements and Equipment	156,396	63,245
Construction in progress	189,375	184,951
Total cost	362,247	265,521
Owned Properties | Suwanee, Georgia (Atlanta-Suwanee)
Real Estate Properties [Line Items]
Land	3,521	3,521
Buildings, Improvements and Equipment	174,124	166,298
Construction in progress	5,559	3,188
Total cost	183,204	173,007
Owned Properties | Piscataway New Jersey
Real Estate Properties [Line Items]
Land	7,466	7,466
Buildings, Improvements and Equipment	103,553	97,806
Construction in progress	36,056	33,472
Total cost	147,075	138,744
Owned Properties | Manassas, Virginia
Real Estate Properties [Line Items]
Construction in progress	57,662	45,194
Total cost	57,662	45,194
Owned Properties | Santa Clara, California
Real Estate Properties [Line Items]
Buildings, Improvements and Equipment	114,499	98,548
Construction in progress	1,238	7,600
Total cost	115,737	106,148
Owned Properties | Dulles, Virginia
Real Estate Properties [Line Items]
Land	3,154	3,154
Buildings, Improvements and Equipment	48,651	72,435
Construction in progress	4,688	3,852
Total cost	56,493	79,441
Owned Properties | Fort Worth, Texas
Real Estate Properties [Line Items]
Land	9,079	9,079
Buildings, Improvements and Equipment	55,018	18,623
Construction in progress	35,722	43,715
Total cost	99,819	71,417
Owned Properties | Sacramento, California
Real Estate Properties [Line Items]
Land	1,481	1,481
Buildings, Improvements and Equipment	65,258	64,874
Construction in progress	163	92
Total cost	66,902	66,447
Owned Properties | Princeton, New Jersey
Real Estate Properties [Line Items]
Land	20,700	20,700
Buildings, Improvements and Equipment	35,192	34,046
Construction in progress	39	431
Total cost	55,931	55,177
Owned Properties | Hillsboro, Oregon
Real Estate Properties [Line Items]
Construction in progress	63,573	39,835
Total cost	63,573	39,835
Owned Properties | Phoenix, Arizona
Real Estate Properties [Line Items]
Buildings, Improvements and Equipment	2,412
Construction in progress	31,840	29,562
Total cost	34,252	29,562
Owned Properties | Eemshaven, Netherlands
Real Estate Properties [Line Items]
Construction in progress	37,267
Total cost	37,267
Owned Properties | Groningen, Netherlands
Real Estate Properties [Line Items]
Land	2,213
Buildings, Improvements and Equipment	36,163
Construction in progress	120
Total cost	38,496
Owned Properties | Other
Real Estate Properties [Line Items]
Land		2,213
Buildings, Improvements and Equipment		35,720
Construction in progress		113
Total cost		38,046
Leased Properties
Real Estate Properties [Line Items]
Buildings, Improvements and Equipment	82,813	43,347
Construction in progress	666	9,334
Total cost	$ 83,479	$ 52,681
Number of facilities leased | property	7
Leased Properties
Real Estate Properties [Line Items]
Number of facilities leased | property		10