Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current income tax provision:
Federal									$ 32,129	$ 34,124	$ 19,787
State									22,743	16,415	13,178
Total current income tax provision									54,872	50,539	32,965
Deferred income tax (benefit) provision:
Federal									(26,554)	4,645	8,142
Effect of the Tax Act									0	0	(1,441)
State									(16,068)	2,851	2,574
Total deferred income tax (benefit) provision									(42,622)	7,496	9,275
Total income tax provision	$ 22,800	$ 23,949	$ (40,324)	$ 5,825	$ 13,109	$ 15,492	$ 14,168	$ 15,266	$ 12,250	$ 58,035	$ 42,240