Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income
Beginning Balances at Dec. 31, 2018	$ 491,992	$ 276,101	$ 224,035	$ (8,144)
Net income	47,995		47,995
Other comprehensive income (loss), net of tax	14,790			14,790
Amortization of unearned compensation	503	503
Exercise of stock options	162	162
Stock option expense	165	165
Stock issued stock plans	1,390	1,390
Stock issued in Salin acquisition	102,722	102,722
Repurchase of outstanding stock	(1,595)	(1,595)
Cash dividends on common stock	(15,413)		(15,413)
Ending Balances at Sep. 30, 2019	$ 642,711	379,448	256,617	6,646
Cash dividends on common stock, per share	$ 0.34
Beginning Balances at Jun. 30, 2019	$ 626,461	380,735	241,519	4,207
Net income	20,537		20,537
Other comprehensive income (loss), net of tax	2,439			2,439
Amortization of unearned compensation	202	202
Exercise of stock options	7	7
Stock option expense	50	50
Stock issued stock plans	49	49
Repurchase of outstanding stock	(1,595)	(1,595)
Cash dividends on common stock	(5,439)		(5,439)
Ending Balances at Sep. 30, 2019	$ 642,711	379,448	256,617	6,646
Cash dividends on common stock, per share	$ 0.12
Impact of adoption of ASU No. 2016-13	$ (15,635)		(15,635)
Impact of adoption of ASU No. 2016-13 | Accounting Standards Update 2016-13			(15,600)
Beginning Balances at Dec. 31, 2019	656,023	379,853	269,738	6,432
Net income	46,606		46,606
Other comprehensive income (loss), net of tax	16,846			16,846
Amortization of unearned compensation	457	457
Exercise of stock options	157	157
Stock option expense	105	105
Stock issued stock plans	1,244	1,244
Repurchase of outstanding stock	(19,636)	(19,636)
Cash dividends on common stock	(15,874)		(15,874)
Ending Balances at Sep. 30, 2020	$ 670,293	362,180	284,835	23,278
Cash dividends on common stock, per share	$ 0.36
Beginning Balances at Jun. 30, 2020	$ 652,206	361,087	269,849	21,270
Net income	20,312		20,312
Other comprehensive income (loss), net of tax	2,008			2,008
Amortization of unearned compensation	335	335
Exercise of stock options	0	0
Stock option expense	28	28
Stock issued stock plans	730	730
Cash dividends on common stock	(5,326)		(5,326)
Ending Balances at Sep. 30, 2020	$ 670,293	$ 362,180	$ 284,835	$ 23,278
Cash dividends on common stock, per share	$ 0.12