Acquisitions - Preliminary Purchase Price Allocation (Detail) - USD ($)	Mar. 31, 2017	Dec. 31, 2016	Aug. 01, 2016	Mar. 31, 2016	Jan. 15, 2016
Business Acquisition [Line Items]
Assets held for sale	$ 0			$ 0
Goodwill	3,053,026,000	$ 2,986,064,000
Liabilities held for sale	$ 0			$ 0
Digital Realty [Member]
Business Acquisition [Line Items]
Cash and cash equivalents			$ 4,073,000
Accounts receivable			1,507,000
Other current assets			794,000
Property, plant and equipment			143,972,000
Goodwill			48,835,000
Intangible assets			11,758,000
Other assets			81,000
Total assets acquired			211,020,000
Accounts payable and accrued liabilities			(2,044,000)
Other current liabilities			(2,798,000)
Deferred tax liabilities			(42,395,000)
Other liabilities			(755,000)
Net assets acquired			$ 163,028,000
Telecity Group plc [Member]
Business Acquisition [Line Items]
Cash and cash equivalents					$ 73,368,000
Accounts receivable					24,042,000
Other current assets					41,079,000
Assets held for sale					877,650,000
Property, plant and equipment					1,058,583,000
Goodwill					2,215,567,000
Intangible assets					694,243,000
Deferred tax assets					994,000
Other assets					4,102,000
Total assets acquired					4,989,628,000
Accounts payable and accrued liabilities					(84,367,000)
Accrued property, plant and equipment					(3,634,000)
Other current liabilities					(27,333,000)
Liabilities held for sale					(155,650,000)
Capital lease and other financing obligations					(165,365,000)
Mortgage and loans payable					(592,304,000)
Deferred tax liabilities					(176,168,000)
Other liabilities					(40,021,000)
Net assets acquired					$ 3,744,786,000