Cover - shares	6 Months Ended
	Jun. 30, 2021	Jul. 30, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-36109
Entity Registrant Name	QTS Realty Trust, Inc.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	46-2809094
Entity Address, Address Line One	12851 Foster Street
Entity Address, City or Town	Overland Park
Entity Address, State or Province	KS
Entity Address, Postal Zip Code	66213
City Area Code	913
Local Phone Number	312-5503
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001577368
Amendment Flag	false
Class A Common Stock
Document Information [Line Items]
Title of 12(b) Security	Class A common stock, $0.01 par value
Trading Symbol	QTS
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		76,972,731
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		124,481
Series A Redeemable Perpetual Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Preferred Stock, 7.125% Series A Cumulative Redeemable Perpetual, $0.01 par value
Trading Symbol	QTS PRA
Security Exchange Name	NYSE
Series B Convertible Perpetual Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Preferred Stock, 6.50% Series B Cumulative Convertible Perpetual, $0.01 par value
Trading Symbol	QTS PRB
Security Exchange Name	NYSE