Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Entity Registrant Name	QTS Realty Trust, Inc.
Entity Central Index Key	0001577368
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		50,300,171
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		128,408
Qualitytech, LP
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Entity Registrant Name	QualityTech, LP
Entity Central Index Key	0001561164
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31