Components of Income Tax Expense Benefit (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Current, Federal	$ 368,957	$ 363,734	$ 248,172
Current, Foreign	8,513	3,151	4,167
Current, State	42,166	38,987	23,224
Current, Total	419,636	405,872	275,563
Deferred, Federal	(12,092)	(15,912)	41,583
Deferred, Foreign	2,463	5,545
Deferred, State	(820)	(302)	7,525
Deferred, Total	(10,449)	(10,669)	49,108
Provision for income taxes	$ 409,187	$ 395,203	$ 324,671