Income Taxes - Income Tax Expense Reconciliation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income taxes computed at the federal statutory rate	$ 226,387	$ 215,417	$ 201,544
State income taxes, net of federal income tax benefit	47,469	45,770	42,944
Excess tax benefits from equity-based compensation	92,234	101,466	77,478
Other, net	(4,837)	(12,465)	(3,978)
Total	176,785	147,256	162,535
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense	$ 0	$ 0	$ (497)