Income Taxes - Components (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 tax payable
Federal									$ 21,396	$ 13,312	$ 21,413
State									4,387	5,528	3,479
Deferred tax payable
Federal									(375)	1,583	(2,627)
State									(603)	730	212
Income tax expense	$ 9,434	$ 6,502	$ 5,328	$ 3,541	$ 5,699	$ 5,584	$ 5,186	$ 4,684	$ 24,805	$ 21,153	$ 22,477
Effective tax rate									24.30%	29.10%	29.10%