Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effect of Fourth Quarter Events [Line Items]
Revenues	$ 143,897	$ 137,538	$ 131,640	$ 126,292	$ 123,707	$ 125,255	$ 119,167	$ 112,689	$ 539,368	$ 480,818	$ 450,524
Operating income	17,151	15,016	17,859	15,631	4,218	13,606	14,598	28,734	65,657	61,156	18,661
Net income (loss)	(10,660)	6,907	10,209	8,120	(3,606)	6,588	7,535	21,148	14,576	31,665	(7,175)
Net income (loss) attributable to QTS Realty Trust, Inc.	(8,922)	6,925	9,892	8,010	(2,511)	6,637	7,483	19,558	15,906	31,291	(4,460)
Net income (loss) attributable to common stockholders	$ (15,967)	$ (120)	$ 2,847	$ 965	$ (9,556)	$ (408)	$ 438	$ 12,513	$ (12,274)	$ 3,111	$ (21,126)
Basic (in dollars per share)	$ (0.33)	$ (0.07)	$ (0.05)	$ (0.01)	$ (0.20)	$ (0.05)	$ (0.03)	$ 0.20	$ (0.47)	$ (0.09)	$ (0.44)
Diluted (in dollars per share)	$ (0.33)	$ (0.07)	$ (0.05)	$ (0.01)	$ (0.20)	$ (0.05)	$ (0.03)	$ 0.20	$ (0.47)	$ (0.09)	$ (0.44)