Document and Entity Information (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Feb. 18, 2015
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Entity Registrant Name	QTS Realty Trust, Inc.
Entity Central Index Key	0001577368
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Current Fiscal Year End Date	--12-31
Entity Public Float		$ 344.7
Common Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding			29,521,550
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding			133,000