Partners' Capital, Equity and Incentive Compensation Plans (Narrative) (Details) $ / shares in Units, $ in Millions			1 Months Ended	3 Months Ended
	May 04, 2017 item $ / shares	Apr. 05, 2017 $ / shares	Mar. 31, 2017 USD ($) item shares	Mar. 31, 2017 USD ($) security item $ / shares shares	Mar. 31, 2016 $ / shares	May 31, 2015 shares
Partners Capital And Distributions [Line Items]
Number of classes of partnership units outstanding | security				2
Equity based compensation expense unrecognized | $			$ 29.1	$ 29.1
Equity based compensation expense vesting period				1 year 6 months
Equity based compensation awards intrinsic value | $			$ 68.6	$ 68.6
Dividend paid to common stockholders | $ / shares		$ 0.39		$ 0.36	$ 0.32
Dividends payable, date payable		Apr. 05, 2017		Jan. 05, 2017	Jan. 06, 2016
QTS Realty Trust, Inc. Employee Stock Purchase Plan [Member]
Partners Capital And Distributions [Line Items]
Shares reserved for purchase under plan			250,000	250,000
2017 Plan
Partners Capital And Distributions [Line Items]
Minimum period of service	30 days
Minimum hours per week of service | item	30
Subsequent Event [Member] | 2017 Plan
Partners Capital And Distributions [Line Items]
Purchase period per year | item	4
Class O Units [Member]
Partners Capital And Distributions [Line Items]
Nonvested awards outstanding			100,000	100,000
Common Class B [Member]
Partners Capital And Distributions [Line Items]
Number of votes per share | item			50	50
Common Class A [Member]
Partners Capital And Distributions [Line Items]
Shares issued			300,000,000
Common Class A [Member] | 2017 Plan
Partners Capital And Distributions [Line Items]
Discount rate of purchase price of common stock	10.00%
Chief Executive Officer [Member] | Common Class B [Member]
Partners Capital And Distributions [Line Items]
Percentage of operating partnership unit exchanged				2.00%
Minimum | 2017 Plan
Partners Capital And Distributions [Line Items]
Minimum percentage of combined voting power	5.00%
Deductions per paycheck for purchase of share | $ / shares	$ 20
Holding period after purchase of share	1 year
Maximum | 2017 Plan
Partners Capital And Distributions [Line Items]
Deductions per paycheck for purchase of share | $ / shares	$ 1,000
Restricted Class A Common Stock [Member]
Partners Capital And Distributions [Line Items]
Nonvested awards outstanding			500,000	500,000
Options to purchase Class A common stock [Member]
Partners Capital And Distributions [Line Items]
Nonvested awards outstanding			700,000	700,000
2013 Equity Incentive Plan [Member]
Partners Capital And Distributions [Line Items]
Authorized shares to be issued under the plan			1,750,000	1,750,000		4,750,000