Income Taxes (Components of Income Tax Expense/Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current income tax expense (benefit):
Federal	$ 84,560	$ 107,393	$ 63,035
State	74,252	86,578	64,917
Foreign	671	(2,485)	3,513
Total current income tax expense	159,483	191,486	131,465
Deferred income tax (benefit) expense:
Federal	(28,093)	(8,801)	(11,870)
State	(11,671)	(16,390)	(4,600)
Foreign	(1,751)	3,587	0
Total deferred income tax benefit	(41,515)	(21,604)	(16,470)
Income tax expense	$ 117,968	$ 169,882	$ 114,995