Parent Company Only Financial Information (Condensed Statements of Income) (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
Condensed Financial Statements
Net gain on investment securities	$ (751)	$ 2	$ 62	$ 319	$ 94	$ 97	$ (57)	$ 30	$ (368)	$ 164	$ (146)
Total interest income									157,104	170,095	151,264
Other expense	32,264	33,123	31,030	33,566	32,568	31,841	31,282	30,913
Applicable income tax expense	4,263	2,636	1,136	(156)	2,767	3,281	2,238	3,377	7,879	11,663	8,686
Net income	$ 20,573	$ 10,210	$ 4,749	$ (765)	$ 14,860	$ 14,868	$ 9,598	$ 14,369	34,767	53,695	46,255
Bank
Condensed Financial Statements
Dividends from subsidiary bank									49,000	37,000	13,500
Non-Bank
Condensed Financial Statements
Dividends from subsidiary bank									0	0	2,500
Holding Company
Condensed Financial Statements
Net gain on investment securities									8	0	0
Interest and other income									16	81	357
Total interest income									49,016	37,081	16,357
Interest on junior subordinated debentures held by subsidiary trust									373	534	520
Payment for Administrative Fees									1,369	1,607	1,561
Other expense									5,376	5,432	4,647
Total expense									7,118	7,573	6,728
Income before federal income taxes and equity in undistributed earnings of subsidiaries									41,898	29,508	9,629
Applicable income tax expense									(1,128)	(1,670)	(2,511)
(Excess dividends from) equity in undistributed earnings of subsidiaries									(8,259)	22,517	34,115
Net income									$ 34,767	$ 53,695	$ 46,255