Income Taxes - Summary of Differences Between Income Tax Expense Computed at Statutory Federal Income Tax Rate and Per Consolidated Statements of Operations (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]
Tax expense at federal rate of 35%													$ 15,250	$ 64,953		$ 39,680
State income taxes, net of federal benefit													(2,238)	7,060		(2,462)
Change in valuation allowance													(1,884)	(8,524)		(9,066)
Foreign tax rate differential													(15,622)	(11,830)		(5,710)
Unrecognized tax benefit increase													3,007	1,045		2,977
Tax effect of foreign operations													5,532	5,988		261
Acquisition costs													0	28		0
Tax benefit of research & development													(1,904)	(1,088)		(871)
Transition tax													20,867	0		0
Revaluation of deferred tax balances													14,953	0		0
Performance based compensation													2,081	0		0
Domestic production activities deduction													(3,793)	(700)		0
Other													2,188	(886)		3,128
Income tax provision	$ 65,758	$ (2,233)	$ (20,914)	$ (4,174)	$ 43,171		$ (6,426)		$ (17,669)		$ 36,970		$ 38,437	$ 56,046	[1]	$ 27,937

[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.