INTERIM CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	QualityTech, LP	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment QualityTech, LP	Series A Preferred Stock	Series A Preferred Stock QualityTech, LP	Series B Preferred Stock	Series B Preferred Stock QualityTech, LP	Total stockholders' equity	Total stockholders' equity Cumulative Effect, Period of Adoption, Adjustment	Total stockholders' equity Series A Preferred Stock	Total stockholders' equity Series B Preferred Stock	Preferred Stock	Preferred Stock QualityTech, LP Limited Partner	Common stock	Common stock QualityTech, LP Limited Partner	Common stock QualityTech, LP General Partner	Common stock Cumulative Effect, Period of Adoption, Adjustment QualityTech, LP Limited Partner	Common stock Series A Preferred Stock QualityTech, LP Limited Partner	Common stock Series B Preferred Stock QualityTech, LP Limited Partner	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated other comprehensive income (loss) QualityTech, LP	Accumulated dividends in excess of earnings	Accumulated dividends in excess of earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated dividends in excess of earnings Series A Preferred Stock	Accumulated dividends in excess of earnings Series B Preferred Stock	Noncontrolling interests
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member	us-gaap:AccountingStandardsUpdate201602Member
Beginning balance, shares at Dec. 31, 2018													7,443	7,443	51,123	57,799	1
Beginning balance at Dec. 31, 2018	$ 1,296,687	$ 1,296,687	$ (1,813)	$ (1,813)					$ 1,193,986	$ (1,813)			$ 407,477	$ 407,477	$ 511	$ 886,866	$ 0	$ (1,813)			$ 1,062,473	$ 2,073	$ 2,344	$ (278,548)	$ (1,813)			$ 102,701
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net share activity through equity award plan (in shares)															231	229
Net share activity through equity award plan	741	741							663						$ 3	$ 741					660							78
Increase (decrease) in fair value of derivative contracts	(9,853)	(9,853)							(8,775)													(8,775)	(9,853)					(1,078)
Equity-based compensation expense	3,300	3,300							2,928							$ 3,300					2,928							372
Adjustment to expenses net from Series B Convertible Preferred stock offering	(42)	(42)							(42)				(42)	(42)
Proceeds net of fees from common equity offering (in shares)															4,000	4,000
Proceeds net of fees from common equity offering	158,663	158,663							148,690						$ 40	$ 158,663					148,650							9,973
Dividends declared on Preferred Stock					$ (1,906)	$ (1,906)	$ (5,139)	$ (5,139)			$ (1,906)	$ (5,139)							$ (1,906)	$ (5,139)						$ (1,906)	$ (5,139)
Dividends declared to common stockholders	(24,371)	(24,371)							(24,371)							(24,371)								(24,371)
Dividends declared to noncontrolling interests	(2,935)								0																			(2,935)
Partnership distributions		(2,935)														(2,935)
Net income	21,148	21,148							19,558							21,148								19,558				1,590
Ending balance at Mar. 31, 2019	1,434,480	1,434,480							1,323,779				$ 407,435	$ 407,435	$ 554	$ 1,034,554	$ 0				1,214,711	(6,702)	(7,509)	(292,219)				110,701
Ending balance, shares at Mar. 31, 2019													7,443	7,443	55,354	62,028	1
Beginning balance, shares at Dec. 31, 2018													7,443	7,443	51,123	57,799	1
Beginning balance at Dec. 31, 2018	1,296,687	1,296,687	$ (1,813)	$ (1,813)					1,193,986	$ (1,813)			$ 407,477	$ 407,477	$ 511	$ 886,866	$ 0	$ (1,813)			1,062,473	2,073	2,344	(278,548)	$ (1,813)			102,701
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (decrease) in fair value of derivative contracts	(34,192)	(34,192)
Dividends declared on Preferred Stock	(21,135)	(21,135)
Net income	35,271	35,271
Ending balance at Sep. 30, 2019	1,473,812	1,473,812							1,364,261				$ 407,435	$ 407,435	$ 582	$ 1,098,651	$ 0				1,326,087	(28,900)	(32,274)	(340,943)				109,551
Ending balance, shares at Sep. 30, 2019													7,443	7,443	58,238	64,906	1
Beginning balance, shares at Mar. 31, 2019													7,443	7,443	55,354	62,028	1
Beginning balance at Mar. 31, 2019	1,434,480	1,434,480							1,323,779				$ 407,435	$ 407,435	$ 554	$ 1,034,554	$ 0				1,214,711	(6,702)	(7,509)	(292,219)				110,701
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net share activity through equity award plan (in shares)															37	31
Net share activity through equity award plan	179	179							505							$ 179					505							(326)
Increase (decrease) in fair value of derivative contracts	(18,606)	(18,606)							(16,608)													(16,608)	(18,606)					(1,998)
Equity-based compensation expense	4,296	4,296							3,832							4,296					3,832							464
Dividends declared on Preferred Stock					(1,906)	(1,906)	(5,139)	(5,139)			(1,906)	(5,139)							(1,906)	(5,139)						(1,906)	(5,139)
Dividends declared to common stockholders	(24,377)	(24,377)							(24,377)							(24,377)								(24,377)
Dividends declared to noncontrolling interests	(2,932)								0																			(2,932)
Partnership distributions		(2,932)														(2,932)
Net income	7,535	7,535							7,483							7,535								7,483				52
Ending balance at Jun. 30, 2019	1,393,530	1,393,530							1,287,569				$ 407,435	$ 407,435	$ 554	$ 1,012,210	$ 0				1,219,048	(23,310)	(26,115)	(316,158)				105,961
Ending balance, shares at Jun. 30, 2019													7,443	7,443	55,391	62,059	1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net share activity through equity award plan (in shares)															15	15
Net share activity through equity award plan	260	260							239							$ 260					239							21
Increase (decrease) in fair value of derivative contracts	(5,733)	(5,733)							(5,207)													(5,207)	(5,733)					(526)
Foreign currency translation adjustments	(426)	(426)							(383)													(383)	(426)					(43)
Equity-based compensation expense	4,457	4,457							3,979							$ 4,457					3,979							478
Proceeds net of fees from settlement of forward shares (in shares)															2,832	2,832
Proceeds net of fees from settlement of forward shares	109,490	109,490							102,849						$ 28	$ 109,490					102,821							6,641
Dividends declared on Preferred Stock	(7,045)	(7,045)			(1,906)	(1,906)	(5,139)	(5,139)			(1,906)	(5,139)							(1,906)	(5,139)						(1,906)	(5,139)
Dividends declared to common stockholders	(24,377)	(24,377)							(24,377)							(24,377)								(24,377)
Dividends declared to noncontrolling interests	(2,932)								0																			(2,932)
Partnership distributions		(2,932)														(2,932)
Net income	6,588	6,588							6,637							6,588								6,637				(49)
Ending balance at Sep. 30, 2019	1,473,812	1,473,812							1,364,261				$ 407,435	$ 407,435	$ 582	$ 1,098,651	$ 0				1,326,087	(28,900)	(32,274)	(340,943)				109,551
Ending balance, shares at Sep. 30, 2019													7,443	7,443	58,238	64,906	1
Beginning balance, shares at Dec. 31, 2019													7,443	7,443	58,228	64,901	1
Beginning balance at Dec. 31, 2019	1,444,451	1,444,451							1,337,817				$ 407,435	$ 407,435	$ 582	$ 1,064,481	$ 0				1,330,444	(24,642)	(27,465)	(376,002)				106,634
Partners' Capital, Beginning Balance at Dec. 31, 2019		1,444,451
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net share activity through equity award plan (in shares)															240	238
Net share activity through equity award plan	(1,458)	(1,458)							(1,309)						$ 3	$ (1,458)					(1,312)							(149)
Increase (decrease) in fair value of derivative contracts	(36,715)	(36,715)							(33,155)													(33,155)	(36,715)					(3,560)
Foreign currency translation adjustments	(223)	(223)							(201)													(201)	(223)					(22)
Equity-based compensation expense	4,875	4,875							4,377							$ 4,875					4,377							498
Proceeds net of fees from settlement of forward shares (in shares)															1,930	1,930
Proceeds net of fees from settlement of forward shares	83,217	83,217							78,535						$ 19	$ 83,217					78,516							4,682
Dividends declared on Preferred Stock					(1,906)	(1,906)	(5,139)	(5,139)			(1,906)	(5,139)							(1,906)	(5,139)						(1,906)	(5,139)
Dividends declared to common stockholders	(28,393)	(28,393)							(28,393)							(28,393)								(28,393)
Dividends declared to noncontrolling interests	(3,133)								0																			(3,133)
Partnership distributions		(3,133)														(3,133)
Net income	8,120	8,120							8,010							8,120								8,010				110
Ending balance at Mar. 31, 2020	$ 1,463,696	1,463,696							1,358,636				$ 407,435	$ 407,435	$ 604	$ 1,120,664	$ 0				1,412,025	(57,998)	(64,403)	(403,430)				105,060
Ending balance, shares at Mar. 31, 2020													7,443	7,443	60,398	67,069	1
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201815Member
Beginning balance, shares at Dec. 31, 2019													7,443	7,443	58,228	64,901	1
Beginning balance at Dec. 31, 2019	$ 1,444,451	1,444,451							1,337,817				$ 407,435	$ 407,435	$ 582	$ 1,064,481	$ 0				1,330,444	(24,642)	(27,465)	(376,002)				106,634
Partners' Capital, Beginning Balance at Dec. 31, 2019		1,444,451
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (decrease) in fair value of derivative contracts	(34,856)	(34,856)
Dividends declared on Preferred Stock	(21,135)	(21,135)
Net income	25,236	25,236
Ending balance at Sep. 30, 2020	1,621,836	1,621,836							1,508,114				$ 407,435	$ 407,435	$ 644	$ 1,276,715	$ 0				1,614,508	(56,480)	(62,314)	(457,993)				113,722
Ending balance, shares at Sep. 30, 2020													7,443	7,443	64,442	71,101	1
Partners' Capital, Ending Balance at Sep. 30, 2020		1,621,836
Beginning balance, shares at Mar. 31, 2020													7,443	7,443	60,398	67,069	1
Beginning balance at Mar. 31, 2020	1,463,696	1,463,696							1,358,636				$ 407,435	$ 407,435	$ 604	$ 1,120,664	$ 0				1,412,025	(57,998)	(64,403)	(403,430)				105,060
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net share activity through equity award plan (in shares)															1	1
Net share activity through equity award plan	(1,360)	(1,360)							(1,225)							$ (1,360)					(1,225)							(135)
Increase (decrease) in fair value of derivative contracts	(3,641)	(3,641)							(3,382)													(3,382)	(3,641)					(259)
Foreign currency translation adjustments	64	64							58													58	64					6
Equity-based compensation expense	6,081	6,081							5,477							$ 6,081					5,477							604
Proceeds net of fees from settlement of forward shares (in shares)															1,033	1,032
Proceeds net of fees from settlement of forward shares	50,455	50,455							47,178						$ 10	$ 50,455					47,168							3,277
Dividends declared on Preferred Stock					(1,906)	(1,906)	(5,139)	(5,139)			(1,906)	(5,139)							(1,906)	(5,139)						(1,906)	(5,139)
Dividends declared to common stockholders	(28,389)	(28,389)							(28,389)							(28,389)								(28,389)
Dividends declared to noncontrolling interests	(3,134)								0																			(3,134)
Partnership distributions		(3,134)														(3,134)
Net income	10,209	10,209							9,892							10,209								9,892				317
Ending balance at Jun. 30, 2020	1,486,936	1,486,936							1,381,200				$ 407,435	$ 407,435	$ 614	$ 1,147,481	$ 0				1,463,445	(61,322)	(67,980)	(428,972)				105,736
Ending balance, shares at Jun. 30, 2020													7,443	7,443	61,432	68,102	1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net share activity through equity award plan (in shares)															62	51
Net share activity through equity award plan	1,397	1,397							1,261						$ 1	$ 1,397					1,260							136
Increase (decrease) in fair value of derivative contracts	5,500	5,500							4,692													4,692	5,500					808
Foreign currency translation adjustments	166	166							150													150	166					16
Equity-based compensation expense	8,247	8,247							7,443							$ 8,247					7,443							804
Proceeds net of fees from settlement of forward shares (in shares)															2,948	2,948
Proceeds net of fees from settlement of forward shares	151,758	151,758							142,389						$ 29	$ 151,758					142,360							9,369
Dividends declared on Preferred Stock	(7,045)	(7,045)			$ (1,906)	$ (1,906)	$ (5,139)	$ (5,139)			$ (1,906)	$ (5,139)							$ (1,906)	$ (5,139)						$ (1,906)	$ (5,139)
Dividends declared to common stockholders	(28,901)	(28,901)							(28,901)							(28,901)								(28,901)
Dividends declared to noncontrolling interests	(3,129)								0																			(3,129)
Partnership distributions		(3,129)														(3,129)
Net income	6,907	6,907							6,925							6,907								6,925				(18)
Ending balance at Sep. 30, 2020	$ 1,621,836	1,621,836							$ 1,508,114				$ 407,435	$ 407,435	$ 644	$ 1,276,715	$ 0				$ 1,614,508	$ (56,480)	$ (62,314)	$ (457,993)				$ 113,722
Ending balance, shares at Sep. 30, 2020													7,443	7,443	64,442	71,101	1
Partners' Capital, Ending Balance at Sep. 30, 2020		$ 1,621,836