Income Taxes - Income Tax Expense Reconciliation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income taxes computed at the federal statutory rate	$ 201,544	$ 296,419	$ 231,595
State income taxes, net of federal income tax benefit	42,944	30,046	23,738
Excess tax benefits from equity-based compensation	77,478	58,681	0
Remeasurement of net deferred tax assets due to enactment of Tax Cut and Jobs Act	(497)	62,702	0
Other, net	(3,978)	(21,096)	(18,898)
Total	$ 162,535	$ 309,390	$ 236,435