Summary of Significant Accounting Policies - Additional Information (Detail) (QualityTech, LP [Member], USD $)	3 Months Ended		9 Months Ended					9 Months Ended			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended				9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Subsidiaries	Sep. 30, 2012	Dec. 31, 2012	Feb. 29, 2012 Interest Rate Swap [Member] Cash Flow Hedging [Member]	Feb. 08, 2012 Interest Rate Swap [Member] Cash Flow Hedging [Member]	Sep. 30, 2013 Customer One [Member]	Sep. 30, 2013 Customer Two [Member]	Sep. 30, 2013 Five Customers [Member]	Sep. 30, 2013 Revolving Credit Loan and Term Loan [Member]	Sep. 30, 2012 Revolving Credit Loan and Term Loan [Member]	Sep. 30, 2013 Revolving Credit Loan and Term Loan [Member]	Sep. 30, 2012 Revolving Credit Loan and Term Loan [Member]	Sep. 30, 2013 In Place Leases [Member]	Sep. 30, 2012 In Place Leases [Member]	Sep. 30, 2013 In Place Leases [Member]	Sep. 30, 2012 In Place Leases [Member]	Sep. 30, 2013 Tenant Relationship [Member]	Sep. 30, 2012 Tenant Relationship [Member]	Sep. 30, 2013 Tenant Relationship [Member]	Sep. 30, 2012 Tenant Relationship [Member]	Sep. 30, 2013 Minimum [Member] Land, Buildings and Improvements [Member]	Sep. 30, 2013 Minimum [Member] Other Customers [Member]	Sep. 30, 2013 Maximum [Member] Land, Buildings and Improvements [Member]	Sep. 30, 2013 Maximum [Member] Leasehold Improvements [Member]	Sep. 30, 2013 Maximum [Member] Other Customers [Member]	Sep. 30, 2013 Maximum [Member] Five Customers [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life of property			40 years																				20 years		40 years	20 years
Depreciation expense from operation	$ 9,700,000	$ 7,600,000	$ 27,200,000	$ 21,500,000
Real estate cost capitalized excluding interest cost	2,400,000	1,800,000	6,300,000	5,300,000
Real estate interest cost capitalized incurred	900,000	400,000	3,000,000	1,500,000
Amortization of lease cost															500,000	0	1,500,000	0	400,000	200,000	1,200,000	600,000
Impairment losses	0	0	0	0
Amortization of the deferred financing costs			2,193,000	2,582,000							600,000	800,000	2,193,000	2,582,000
Written off of unamortized debt cost				1,434,000									2,000,000
Written off Unamortization cost relation to Assets securitization			1,300,000
Amortization of deferred leasing costs totaled			3,200,000	2,400,000
Deferred income	7,561,000		7,561,000		6,745,000
Amortization of deferred revenue	1,300,000	1,200,000	3,500,000	3,000,000
Notional amount of derivative						150,000,000	150,000,000
Company recorded equity-based compensation expense net of repurchased awards acquired	500,000	100,000	1,300,000	300,000
Amount of the straight-line rent receivable on the balance sheets included in rents and other receivables	2,800,000		2,800,000		2,400,000
Aggregate allowance for doubtful accounts	400,000		400,000		500,000
Outstanding liabilities for the capital leases	1,995,000		1,995,000		2,491,000
Restructuring reserve		3,300,000		3,300,000
Restructuring cost			$ 0
Percentage of rental revenue earned								7.00%	6.00%																		5.00%
Percentage of total accounts receivable										5.00%														10.00%				36.00%
Number of subsidiaries taxed as taxable REIT			1