Earnings per share of QTS Realty Trust, Inc. (Antidilutive) (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 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	6,674
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	655
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	6,749	6,729