Income Taxes - Summary of Differences Between Income Tax Expense Computed at Statutory Federal Income Tax Rate and Per Consolidated Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Tax expense at federal rate of 35%											$ 64,953	$ 39,680	$ 34,569
State income taxes, net of federal benefit											7,060	(2,462)	(544)
Change in valuation allowance											(8,524)	(9,066)	3,521
Foreign tax rate differential											(11,830)	(5,710)	(5,508)
Unrecognized tax benefit increase											1,045	2,977	65
Tax effect of foreign operations											5,988	261	(104)
Acquisition costs											28		289
Tax benefit of research & development											(1,088)	(871)	(3,446)
Other											(1,586)	3,128	2,367
Income tax provision	$ 43,171	$ (6,426)	$ (17,669)		$ 36,970		$ 18,856	$ 3,786	$ 5,825	$ (530)	$ 56,046	$ 27,937	$ 31,209

[1] As previously discussed in Note 1, Nature of Business and Summary of Significant Accounting Policies, the Company adopted 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.