Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2019	[1]	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
Federal
Current										$ 18,918	$ 13,616	$ 32,282
Deferred										(406)	3,517	13,980
Total Federal										18,512	17,133	46,262
State
Current										589	720	323
Deferred										25	(8)	(148)
Total State										614	712	175
Total Federal and State	$ 5,091		$ 4,743	$ 5,070	$ 4,222	$ 4,952	$ 2,876	$ 4,010	$ 6,007	$ 19,126	$ 17,845	$ 46,437

[1] The DNB Merger is included in our consolidated financial statements beginning on December 1, 2019.