Income Taxes (Schedule of Components of the Provision for Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Expense (Benefit), Continuing Operations, by Jurisdiction [Abstract]
Federal income tax expense, current	$ 315,061	$ 289,953	$ 467,577
State income tax expense, current	62,795	59,487	41,183
International income tax expense, current	273	0	0
Current income tax expense	378,129	349,440	508,760
Federal income tax expense (benefit), deferred	19,367	16,309	(13,053)
State income tax expense, deferred	2,027	3,851	8,293
International income tax benefit	(236)	0	0
Total deferred	21,158	20,160	(4,760)
Provision for income taxes	$ 399,287	$ 369,600	$ 504,000