Goodwill and Intangible Assets - Summary of Acquired Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	$ 318,080	$ 318,080
Finite-lived intangible assets, Accumulated Amortization	(62,470)	(46,655)
Finite-lived intangible assets, Other	3,986	3,245
Finite-lived intangible assets, Net Carrying Amount	259,596	274,670
Indefinite-lived intangible assets, Net Carrying Amount	86,832	86,832
Gross amounts of intangible assets	404,912	404,912
Intangible Assets, Net Carrying Amount	346,428	361,502
IPR&D [Member]
Acquired Intangible Assets [Line Items]
Indefinite-lived intangible assets, Net Carrying Amount	86,832	86,832
Developed technology [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	125,889	125,889
Finite-lived intangible assets, Accumulated Amortization	(23,780)	(19,317)
Finite-lived intangible assets, Other	2,257	1,847
Finite-lived intangible assets, Net Carrying Amount	104,366	108,419
Trade name [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	45,275	45,275
Finite-lived intangible assets, Accumulated Amortization	(19,224)	(10,924)
Finite-lived intangible assets, Other	320	261
Finite-lived intangible assets, Net Carrying Amount	26,371	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	(10,583)	(8,639)
Finite-lived intangible assets, Net Carrying Amount	102,234	104,178
Other [Member]
Acquired Intangible Assets [Line Items]
Gross amounts of finite-lived intangible assets	34,099	34,099
Finite-lived intangible assets, Accumulated Amortization	(8,883)	(7,775)
Finite-lived intangible assets, Other	1,409	1,137
Finite-lived intangible assets, Net Carrying Amount	$ 26,625	$ 27,461