Segment Information - Revenue Information on Services Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue from External Customer [Line Items]
Revenue	$ 665,582	$ 605,161	$ 1,308,756	$ 1,185,214
Recurring Revenues [Member]
Revenue from External Customer [Line Items]
Revenue	626,691	574,158	1,236,348	1,123,861
Recurring Revenues [Member] | Colocation [Member]
Revenue from External Customer [Line Items]
Revenue	496,610	452,660	978,155	887,283
Recurring Revenues [Member] | Interconnection [Member]
Revenue from External Customer [Line Items]
Revenue	104,661	90,969	206,319	177,995
Recurring Revenues [Member] | Managed infrastructure services [Member]
Revenue from External Customer [Line Items]
Revenue	23,466	27,856	47,321	53,240
Recurring Revenues [Member] | Rental [Member]
Revenue from External Customer [Line Items]
Revenue	1,954	2,673	4,553	5,343
Non-recurring Revenues [Member]
Revenue from External Customer [Line Items]
Revenue	$ 38,891	$ 31,003	$ 72,408	$ 61,353