Real Estate Assets and Construction in Progress (Summary of Properties Owned or Leased by the Company) (Details) $ in Thousands		Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($)
Real Estate Properties [Line Items]
Land		$ 57,112	$ 48,577
Buildings and improvements		1,180,386	914,286
Construction in progress		345,655	214,719
Total cost		1,583,153	1,177,582
Owned Properties [Member]
Real Estate Properties [Line Items]
Land		55,982	48,577
Buildings and improvements		1,061,247	886,116
Construction in progress		336,034	213,772
Total cost		1,453,263	1,148,465
Owned Properties [Member] | Suwanee, Georgia (Atlanta-Suwanee) [Member]
Real Estate Properties [Line Items]
Land		3,521	3,521
Buildings and improvements		150,028	138,991
Construction in progress		15,330	6,345
Total cost		168,879	148,857
Owned Properties [Member] | Atlanta, Georgia (Atlanta-Metro) [Member]
Real Estate Properties [Line Items]
Land		15,397	15,397
Buildings and improvements		406,190	356,122
Construction in progress		41,835	22,693
Total cost		$ 463,422	$ 394,212
Owned Properties [Member] | Santa Clara, California [Member]
Real Estate Properties [Line Items]
Land	[1]
Buildings and improvements	[1]	$ 94,437	$ 90,332
Construction in progress	[1]	1,379	650
Total cost	[1]	95,816	90,982
Owned Properties [Member] | Richmond, Virginia [Member]
Real Estate Properties [Line Items]
Land		2,180	2,180
Buildings and improvements		208,654	127,080
Construction in progress		85,771	71,794
Total cost		296,605	201,054
Owned Properties [Member] | Sacramento, California [Member]
Real Estate Properties [Line Items]
Land		1,481	1,481
Buildings and improvements		61,462	60,094
Construction in progress		73	278
Total cost		63,016	61,853
Owned Properties [Member] | Princeton, New Jersey [Member]
Real Estate Properties [Line Items]
Land		20,700	17,976
Buildings and improvements		32,708	35,951
Construction in progress		422	90
Total cost		53,830	54,017
Owned Properties [Member] | Dallas-Fort Worth, Texas [Member]
Real Estate Properties [Line Items]
Land		8,590	5,808
Buildings and improvements		71,783	44,053
Construction in progress		120,331	89,982
Total cost		$ 200,704	$ 139,843
Owned Properties [Member] | Chicago, Illinois [Member]
Real Estate Properties [Line Items]
Land
Construction in progress		$ 70,749	$ 21,786
Total cost		70,749	21,786
Owned Properties [Member] | Miami, Florida [Member]
Real Estate Properties [Line Items]
Land		1,777	1,777
Buildings and improvements		30,554	28,786
Construction in progress		144	129
Total cost		32,475	30,692
Owned Properties [Member] | Lenexa, Kansas [Member]
Real Estate Properties [Line Items]
Land		437	437
Buildings and improvements		$ 3,511	3,298
Construction in progress			25
Total cost		$ 3,948	$ 3,760
Owned Properties [Member] | Wichita, Kansas [Member]
Real Estate Properties [Line Items]
Land
Buildings and improvements			$ 1,409
Construction in progress
Total cost			$ 1,409
Owned Properties [Member] | Deluth, Georgia [Member]
Real Estate Properties [Line Items]
Land		1,899
Buildings and improvements		$ 1,920
Construction in progress
Total cost		$ 3,819
Leased Properties [Member]
Real Estate Properties [Line Items]
Land		1,130
Buildings and improvements		119,139	$ 28,170
Construction in progress		9,621	947
Total cost		$ 129,890	$ 29,117
Leased Properties [Member] | Jersey City, New Jersey [Member]
Real Estate Properties [Line Items]
Land
Buildings and improvements		$ 28,228	$ 27,318
Construction in progress		2,421	920
Total cost		$ 30,649	$ 28,238
Leased Properties [Member] | Overland Park, Kansas [Member]
Real Estate Properties [Line Items]
Land
Buildings and improvements	[2]	$ 922	$ 852
Construction in progress		4	27
Total cost		926	$ 879
Leased Properties [Member] | Carpathia Properties [Member]
Real Estate Properties [Line Items]
Land	[3]	1,130
Buildings and improvements	[3]	89,989
Construction in progress	[3]	7,196
Total cost	[3]	$ 98,315
Number of facilities leased | property		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.*** Includes 13 facilities. All facilities are leased, including those subject to capital leases.

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