Acquisitions and Divestitures - Allocation of Purchase Price (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Oct. 01, 2015	Dec. 31, 2014	Jul. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 2,690,636		$ 1,451,887
Airvana LP [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		$ 600
Accounts receivable		4,200
Other current assets		3,700
Property, plant and equipment		2,500
Goodwill		20,200
Identifiable intangible assets		19,100
Less: Liabilities assumed		(5,200)
Net acquisition cost		$ 45,100
Alifabs Group [Member]
Business Acquisition [Line Items]
Cash and cash equivalents				$ 2,100
Other current assets				15,700
Goodwill				15,300
Identifiable intangible assets				26,900
Other noncurrent assets				600
Less: Liabilities assumed				(11,800)
Net acquisition cost				$ 48,800