Real Estate Assets and Construction in Progress (Summary of Properties Owned or Leased by the Company) (Details) $ in Thousands		Mar. 31, 2016 USD ($) property	Dec. 31, 2015 USD ($) property
Real Estate Properties [Line Items]
Land		$ 57,128	$ 57,112
Buildings, improvements and equipment		1,241,885	1,180,386
Construction in progress		340,511	345,655
Total cost		1,639,524	1,583,153
Owned Properties [Member]
Real Estate Properties [Line Items]
Land		55,998	55,982
Buildings, improvements and equipment		1,124,686	1,061,247
Construction in progress		331,105	336,034
Total cost		1,511,789	1,453,263
Owned Properties [Member] | Suwanee, Georgia (Atlanta-Suwanee) [Member]
Real Estate Properties [Line Items]
Land		3,521	3,521
Buildings, improvements and equipment		152,083	150,028
Construction in progress		15,344	15,330
Total cost		170,948	168,879
Owned Properties [Member] | Atlanta, Georgia (Atlanta-Metro) [Member]
Real Estate Properties [Line Items]
Land		15,397	15,397
Buildings, improvements and equipment		418,313	406,190
Construction in progress		35,201	41,835
Total cost		$ 468,911	$ 463,422
Owned Properties [Member] | Santa Clara, California [Member]
Real Estate Properties [Line Items]
Land	[1]
Buildings, improvements and equipment	[1]	$ 95,395	$ 94,437
Construction in progress	[1]	1,403	1,379
Total cost	[1]	96,798	95,816
Owned Properties [Member] | Richmond, Virginia [Member]
Real Estate Properties [Line Items]
Land		2,180	2,180
Buildings, improvements and equipment		211,109	208,654
Construction in progress		86,935	85,771
Total cost		300,224	296,605
Owned Properties [Member] | Sacramento, California [Member]
Real Estate Properties [Line Items]
Land		1,481	1,481
Buildings, improvements and equipment		61,574	61,462
Construction in progress		37	73
Total cost		63,092	63,016
Owned Properties [Member] | Princeton, New Jersey [Member]
Real Estate Properties [Line Items]
Land		20,700	20,700
Buildings, improvements and equipment		32,734	32,708
Construction in progress		450	422
Total cost		53,884	53,830
Owned Properties [Member] | Dallas-Fort Worth, Texas [Member]
Real Estate Properties [Line Items]
Land		8,606	8,590
Buildings, improvements and equipment		117,415	71,783
Construction in progress		94,475	120,331
Total cost		$ 220,496	$ 200,704
Owned Properties [Member] | Chicago, Illinois [Member]
Real Estate Properties [Line Items]
Land
Buildings, improvements and equipment
Construction in progress		$ 96,956	$ 70,749
Total cost		96,956	70,749
Owned Properties [Member] | Miami, Florida [Member]
Real Estate Properties [Line Items]
Land		1,777	1,777
Buildings, improvements and equipment		30,656	30,554
Construction in progress		263	144
Total cost		32,696	32,475
Owned Properties [Member] | Lenexa, Kansas [Member]
Real Estate Properties [Line Items]
Land		437	437
Buildings, improvements and equipment		$ 3,511	$ 3,511
Construction in progress
Total cost		$ 3,948	$ 3,948
Owned Properties [Member] | Deluth, Georgia [Member]
Real Estate Properties [Line Items]
Land		1,899	1,899
Buildings, improvements and equipment		1,896	$ 1,920
Construction in progress		41
Total cost		3,836	$ 3,819
Leased Properties [Member]
Real Estate Properties [Line Items]
Land		1,130	1,130
Buildings, improvements and equipment		117,199	119,139
Construction in progress		9,406	9,621
Total cost		$ 127,735	$ 129,890
Leased Properties [Member] | Jersey City, New Jersey [Member]
Real Estate Properties [Line Items]
Land
Buildings, improvements and equipment		$ 24,899	$ 28,228
Construction in progress		2,078	2,421
Total cost		$ 26,977	$ 30,649
Leased Properties [Member] | Overland Park, Kansas [Member]
Real Estate Properties [Line Items]
Land
Buildings, improvements and equipment	[2]	$ 922	$ 922
Construction in progress		23	4
Total cost		945	926
Leased Properties [Member] | Carpathia Properties [Member]
Real Estate Properties [Line Items]
Land	[3]	1,130	1,130
Buildings, improvements and equipment	[3]	91,378	89,989
Construction in progress	[3]	7,305	7,196
Total cost	[3]	$ 99,813	$ 98,315
Number of facilities leased | property		13	13

[1] Owned facility subject to long-term ground sublease.

[2] This does not include the portion of the business that is used for QTS office space or other real estate not used by customers.

[3] Includes 13 facilities. All facilities are leased, including those subject to capital leases.