Patent Assets, Net (Detail) - Patent Assets, Net - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Finite-lived Intangible Assets [Roll Forward]
Patent assets, beginning balance			$ 6,890
Patent assets - Additions			36,546	$ 48,936
Patent assets, ending balance	$ 72,855		72,855
Accumulated amortization, beginning balance			(5,089)
Accumulated amortization - Additions	(2,600)	$ (400)	(4,800)	(900)
Accumulated amortization, ending balance	(9,725)		(9,725)
Patent assets, net	212,245		212,245		$ 254,560
Patents
Finite-Lived Intangible Assets [Line Items]
Amortization expense	37,700	$ 35,100	79,500	$ 68,200
Finite-lived Intangible Assets [Roll Forward]
Patent assets, beginning balance			824,258
Patent assets - Additions			37,160
Patent assets - Sales			(3,867)
Patent assets, ending balance	857,551		857,551
Accumulated amortization, beginning balance			(569,698)
Accumulated amortization - Additions			(79,430)
Accumulated amortization - Sales			3,822
Accumulated amortization, ending balance	(645,306)		(645,306)
Patent assets, net	$ 212,245		$ 212,245		$ 254,560
Minimum | Patents
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life			24 months
Maximum | Patents
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life			60 months
Weighted Average | Patents
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	43 months