Intangible Assets - Summary of Acquired Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	$ 302,582	$ 346,082
Finite-lived intangible assets, Accumulated Amortization	(77,850)	(112,710)
Finite-lived intangible assets, Other	1,810	2,094
Finite-lived intangible assets, Net Carrying Amount	226,542	235,466
Indefinite-lived intangible assets, Gross Carrying Amount	60,290	60,290
Indefinite-lived intangible assets, Other	(13,264)	(13,264)
Indefinite-lived intangible assets, Net Carrying Amount	47,026	47,026
Gross amounts of intangible assets	362,872	406,372
Intangible assets, Other	(11,454)	(11,170)
Intangible Assets, Net Carrying Amount	273,568	282,492
IPR&D [Member]
Acquired Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	60,290	60,290
Indefinite-lived intangible assets, Other	(13,264)	(13,264)
Indefinite-lived intangible assets, Net Carrying Amount	47,026	47,026
Developed Technology [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	152,431	152,431
Finite-lived intangible assets, Accumulated Amortization	(46,396)	(40,705)
Finite-lived intangible assets, Other	1,005	1,205
Finite-lived intangible assets, Net Carrying Amount	107,040	112,931
Trade names [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	1,775	45,275
Finite-lived intangible assets, Accumulated Amortization	(624)	(44,056)
Finite-lived intangible assets, Other	143	170
Finite-lived intangible assets, Net Carrying Amount	1,294	1,389
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	(18,345)	(16,409)
Finite-lived intangible assets, Net Carrying Amount	94,472	96,408
Other [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	35,559	35,559
Finite-lived intangible assets, Accumulated Amortization	(12,485)	(11,540)
Finite-lived intangible assets, Other	662	719
Finite-lived intangible assets, Net Carrying Amount	$ 23,736	$ 24,738