Earnings per share of QTS Realty Trust, Inc. (Antidilutive) (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Class A Partnership Units
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Antidilutive shares excluded from the computation of diluted net earning per share	6,671	6,669	6,671	6,671
Class O units, TSR units and options to purchase common stock on an "as if" converted basis
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Antidilutive shares excluded from the computation of diluted net earning per share	1,131	495	1,066
Series B Convertible Perpetual Preferred Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Antidilutive shares excluded from the computation of diluted net earning per share	6,756	6,729	6,753	6,729