Partners' Capital, Equity and Incentive Compensation Plans (Narrative) (Details)		1 Months Ended		3 Months Ended						9 Months Ended
	Oct. 05, 2016 $ / shares	Mar. 31, 2016 USD ($) shares	Jun. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) item $ / shares shares	Jun. 30, 2016 $ / shares	Mar. 31, 2016 $ / shares	Sep. 30, 2015 $ / shares	Jun. 30, 2015 $ / shares	Mar. 31, 2015 $ / shares	Sep. 30, 2016 USD ($) item security shares	Apr. 01, 2016 $ / shares	May 03, 2015 shares
Partners Capital And Distributions [Line Items]
Number of classes of partnership units outstanding | security										2
Equity based compensation expense unrecognized | $				$ 18,700,000						$ 18,700,000
Equity based compensation expense vesting period										4 years
Equity based compensation awards intrinsic value | $				$ 80,100,000						$ 80,100,000
Dividend paid to common stockholders | $ / shares	$ 0.36			$ 0.36	$ 0.36	$ 0.32	$ 0.32	$ 0.32	$ 0.29
Dividends payable, date payable	Oct. 05, 2016			Jul. 06, 2016	Apr. 05, 2016	Jan. 06, 2016	Jul. 08, 2015	Apr. 07, 2015	Jan. 07, 2015
Dividends payable, date of record	Sep. 20, 2016			Jun. 17, 2016	Mar. 18, 2016	Dec. 17, 2015	Jun. 19, 2015	Mar. 20, 2015	Dec. 19, 2014
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
Subsequent Event [Member]
Partners Capital And Distributions [Line Items]
Dividend paid to common stockholders | $ / shares	$ 0.36
Partnership distribution per unit | $ / shares	$ 0.36
Dividends payable, date payable	Oct. 05, 2016
Dividends payable, date of record	Sep. 20, 2016
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		6,325,000
Shares issued, price per share | $ / shares											$ 45.50
Net proceeds from issuance of shares | $		$ 276,000,000
Common Class A [Member] | Underwriters [Member]
Partners Capital And Distributions [Line Items]
Shares issued		825,000
Chief Executive Officer [Member] | Common Class B [Member]
Partners Capital And Distributions [Line Items]
Percentage of operating partnership unit exchanged										2.00%
Minimum [Member] | QTS Realty Trust, Inc. Employee Stock Purchase Plan [Member]
Partners Capital And Distributions [Line Items]
Monthly deduction from eligible employees for plan | $			$ 40
Maximum [Member] | QTS Realty Trust, Inc. Employee Stock Purchase Plan [Member]
Partners Capital And Distributions [Line Items]
Monthly deduction from eligible employees for plan | $			$ 2,000
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				400,000						400,000
2013 Equity Incentive Plan [Member]
Partners Capital And Distributions [Line Items]
Authorized shares to be issued under the plan				4,750,000						4,750,000		1,750,000