Income Taxes - Components of Income Before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Income Tax Disclosure [Abstract]
United States													$ (42,863)	$ 134,740		$ 52,563
Foreign													86,435	50,841		60,810
Income before income taxes	$ 98,922	$ 1,155	$ (50,723)	$ (5,782)	$ 109,862		$ (16,252)		$ (34,143)		$ 126,114		$ 43,572	$ 185,581	[1]	$ 113,373

[1] The Company adopted ASU 2016-09, Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting, ("ASU 2016-09") during the year ended December 31, 2016. The Company elected to early adopt ASU 2016-09 in the third quarter of 2016, which requires it to reflect any adjustments as of January 1, 2016, the beginning of the annual period that includes the interim period of adoption. The impact of the adoption to the Company's previously reported quarterly results for the quarters ended March 31 and June 30, 2016 are reflected in the table above.