Credit Facilities and Mortgages Payable - Outstanding Debt (Detail) (Limited Partner [Member], QualityTech, LP [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Outstanding debt	$ 609,376	$ 487,791
Unsecured Credit Facility [Member]
Debt Instrument [Line Items]
Outstanding debt	520,000
Secured Credit Facility [Member]
Debt Instrument [Line Items]
Outstanding debt		316,500
Richmond Credit Facility [Member]
Debt Instrument [Line Items]
Outstanding debt	70,000	70,000
Atlanta Metro Equipment Loan [Member]
Debt Instrument [Line Items]
Outstanding debt	19,376	20,931
Miami Loan [Member]
Debt Instrument [Line Items]
Outstanding debt		26,048
Atlanta-Suwanee Land Loan [Member]
Debt Instrument [Line Items]
Outstanding debt		1,600
Lenexa Loan [Member]
Debt Instrument [Line Items]
Outstanding debt		2,712
Santa Clara Bridge Loan [Member]
Debt Instrument [Line Items]
Outstanding debt		$ 50,000