Income Taxes - Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ 144,615	$ 252,337	$ 284,199
State	39,326	29,288	41,083
Foreign	77,306	44,896	28,593
Deferred:
Federal	15,167	71,238	26,684
State	5,770	13,663	3,857
Foreign	(17,046)	(18,911)	2,684
Income tax expense, total	$ 265,138	$ 392,511	$ 387,100