Schedule of Amortization of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 382,416	$ 404,475	$ 231,590
Cost of sales
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	3,174	2,963	670
Selling, general and administrative expenses
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	3,835	4,048	3,480
Amortization of acquired intangible assets
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 375,407	$ 397,464	$ 227,440