Income Taxes - Components of Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current
Federal									$ 23,786	$ 22,658	$ 28,380
State									4,264	2,625	1,354
Total									28,050	25,283	29,734
Deferred
Federal									17,331	13,369	22,314
State									2,710	3,075	1,147
Revaluation of net deferred tax assets as a result of the Tax Cuts and Jobs Act									0	0	14,486
Total									20,041	16,444	37,947
Total income tax expense	$ 9,424	$ 11,132	$ 13,945	$ 13,590	$ 13,098	$ 8,532	$ 10,424	$ 9,673	$ 48,091	$ 41,727	$ 67,681