CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Series A Redeemable Perpetual Preferred [Member] Qualitytech, LP Preferred stock Limited Partner	Series A Redeemable Perpetual Preferred [Member] Qualitytech, LP	Series A Redeemable Perpetual Preferred [Member] Preferred stock	Series A Redeemable Perpetual Preferred [Member] Total stockholders' Equity	Series A Redeemable Perpetual Preferred [Member]	Series B Convertible preferred stock Qualitytech, LP Preferred stock Limited Partner	Series B Convertible preferred stock Qualitytech, LP	Series B Convertible preferred stock Preferred stock	Series B Convertible preferred stock Total stockholders' Equity	Series B Convertible preferred stock	Series A Preferred Stock Qualitytech, LP Common stock Limited Partner	Series A Preferred Stock Qualitytech, LP	Series A Preferred Stock Accumulated dividends in excess of earnings	Series A Preferred Stock Total stockholders' Equity	Series A Preferred Stock	Series B Preferred Stock Qualitytech, LP Common stock Limited Partner	Series B Preferred Stock Qualitytech, LP	Series B Preferred Stock Accumulated dividends in excess of earnings	Series B Preferred Stock Total stockholders' Equity	Series B Preferred Stock	Qualitytech, LP Preferred stock Limited Partner	Qualitytech, LP Common stock General Partner	Qualitytech, LP Common stock Limited Partner	Qualitytech, LP Accumulated other comprehensive income	Qualitytech, LP	Preferred stock	Common stock	Additional paid-in capital	Accumulated other comprehensive income	Accumulated dividends in excess of earnings	Total stockholders' Equity	Noncontrolling interests	Total
Beginning balance at Dec. 31, 2015																									$ 719,866		$ 412	$ 670,275		$ (52,732)	$ 617,955	$ 101,911	$ 719,866
Limited Partners' Capital,Beginning balance at Dec. 31, 2015																							$ 719,866
Beginning balance, shares at Dec. 31, 2015																											41,226,000
Beginning balance, shares at Dec. 31, 2015																							48,023,000
Beginning balance, shares at Dec. 31, 2015																						1,000
Net share activity through equity award plan																											$ 3	(3)				(1,726)	(1,726)
Net share activity through equity award plan, shares																							280,000				280,000
Issuance of shares through equity award plan																							$ (1,726)		(1,726)
Equity-based compensation expense																							10,584		10,584			9,229			9,229	1,355	10,584
Net proceeds from stock offering																							$ 275,862		275,862		$ 63	252,282			252,345	23,517	275,862
Net proceeds from stock offering (in shares)																							6,325,000				6,325,000
Dividends to stockholders																							$ (66,586)		(66,586)					(66,586)	(66,586)		(66,586)
Distributions to noncontrolling interests																																(9,875)	(9,875)
Partnership distributions																							(9,875)		(9,875)
Net income (loss)																							24,685		24,685					21,525	21,525	3,160	24,685
Ending balance at Dec. 31, 2016																									952,810		$ 478	931,783		(97,793)	834,468	118,342	952,810
Limited Partners' Capital, Ending balance at Dec. 31, 2016																							$ 952,810
Limited Partners' Capital Ending balance, shares at Dec. 31, 2016																							54,628,000
Ending balance, shares at Dec. 31, 2016																						1,000
Ending balance, shares at Dec. 31, 2016																											47,831,000
Net share activity through equity award plan																							$ 1,022		1,022		$ 6	893			899	123	1,022
Net share activity through equity award plan, shares																							582,000				582,000
Reclassification of noncontrolling interest upon conversion of partnership units to common stock																											$ 3	8,352			8,355	(8,355)
Reclassification of noncontrolling interest upon conversion of partnership units to common stock, shares																											253,000
Increase in fair value of interest rate swaps																								$ 1,449	1,449				$ 1,283		1,283	166	1,449
Equity-based compensation expense																							$ 13,863		13,863			12,196			12,196	1,667	13,863
Net proceeds from stock offering																							$ 107,495		107,495		$ 20	95,952			95,972	11,523	107,495
Net proceeds from stock offering (in shares)																							2,036,000				2,036,000
Dividends to stockholders																							$ (77,041)		(77,041)					(77,041)	(77,041)		(77,041)
Distributions to noncontrolling interests																																(10,399)	(10,399)
Partnership distributions																							(10,399)		(10,399)
Net income (loss)																							1,457		1,457					1,282	1,282	175	1,457
Ending balance at Dec. 31, 2017																								1,449	990,656		$ 507	1,049,176	1,283	(173,552)	877,414	113,242	990,656
Limited Partners' Capital, Ending balance at Dec. 31, 2017																							$ 989,207
Limited Partners' Capital Ending balance, shares at Dec. 31, 2017																							57,246,000
Ending balance, shares at Dec. 31, 2017																						1,000
Partners' Capital, Ending Balance at Dec. 31, 2017																									990,656
Ending balance, shares at Dec. 31, 2017																											50,702,000
Net share activity through equity award plan																							$ (1,788)		(1,788)		$ 4	(2,717)			(2,713)	925	(1,788)
Net share activity through equity award plan, shares																							553,000				421,000
Increase in fair value of interest rate swaps																								895	895				790		790	105	895
Equity-based compensation expense																							$ 18,100		18,100			16,014			16,014	2,086	18,100
Net proceeds from stock offering	$ 103,212	$ 103,212	$ 103,212	$ 103,212	$ 103,212	$ 304,265	$ 304,265	$ 304,265	$ 304,265	$ 304,265
Net proceeds from stock offering (in shares)	4,280,000		4,280,000			3,163,000		3,163,000
Dividends on Preferred Units											$ (6,046)	$ (6,046)	$ (6,046)	$ (6,046)	$ (6,046)	$ (10,621)	$ (10,621)	$ (10,621)	$ (10,621)	$ (10,621)
Dividends to stockholders																							(83,869)		(83,869)					(83,869)	(83,869)		(83,869)
Distributions to noncontrolling interests																																(10,942)	(10,942)
Partnership distributions																							(10,942)		(10,942)
Net income (loss)																							(7,175)		(7,175)					(4,460)	(4,460)	(2,715)	(7,175)
Ending balance at Dec. 31, 2018																								$ 2,344	1,296,687	$ 407,477	$ 511	$ 1,062,473	$ 2,073	$ (278,548)	$ 1,193,986	$ 102,701	$ 1,296,687
Limited Partners' Capital, Ending balance at Dec. 31, 2018																					$ 407,477		$ 886,866
Limited Partners' Capital Ending balance, shares at Dec. 31, 2018																					7,443,000		57,799,000
Ending balance, shares at Dec. 31, 2018																						1,000
Partners' Capital, Ending Balance at Dec. 31, 2018																									$ 1,296,687
Ending balance, shares at Dec. 31, 2018																										7,443,000	51,123,000