Intangible Assets - Summary of Acquired Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	$ 346,082	$ 318,080
Finite-lived intangible assets, Accumulated Amortization	(95,313)	(46,655)
Finite-lived intangible assets, Other	2,611	3,245
Finite-lived intangible assets, Net Carrying Amount	253,380	274,670
Indefinite-lived intangible assets, Gross Carrying Amount	60,290	86,832
Indefinite-lived intangible assets, Other	(13,264)
Indefinite-lived intangible assets, Net Carrying Amount	47,026	86,832
Gross amounts of intangible assets	406,372	404,912
Intangible assets, Other	(10,653)
Intangible Assets, Net Carrying Amount	300,406	361,502
IPR&D [Member]
Acquired Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	60,290	86,832
Indefinite-lived intangible assets, Other	(13,264)
Indefinite-lived intangible assets, Net Carrying Amount	47,026	86,832
Developed technology [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	152,431	125,889
Finite-lived intangible assets, Accumulated Amortization	(29,362)	(19,317)
Finite-lived intangible assets, Other	1,488	1,847
Finite-lived intangible assets, Net Carrying Amount	124,557	108,419
Trade names [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	45,275	45,275
Finite-lived intangible assets, Accumulated Amortization	(43,926)	(10,924)
Finite-lived intangible assets, Other	210	261
Finite-lived intangible assets, Net Carrying Amount	1,559	34,612
Favorable Contracts and Leases Net [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	112,817	112,817
Finite-lived intangible assets, Accumulated Amortization	(12,526)	(8,639)
Finite-lived intangible assets, Net Carrying Amount	100,291	104,178
Other [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	35,559	34,099
Finite-lived intangible assets, Accumulated Amortization	(9,499)	(7,775)
Finite-lived intangible assets, Other	913	1,137
Finite-lived intangible assets, Net Carrying Amount	$ 26,973	$ 27,461