Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total	Cumulative Change, Adjusted Balance [Member] Common Stock [Member]	Cumulative Change, Adjusted Balance [Member] Retained Earnings [Member]	Cumulative Change, Adjusted Balance [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Cumulative Change, Adjusted Balance [Member]	Cumulative Change, Adjustment [Member] Common Stock [Member]	Cumulative Change, Adjustment [Member] Retained Earnings [Member]	Cumulative Change, Adjustment [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Cumulative Change, Adjustment [Member]
Balance at beginning of period at Dec. 31, 2019	$ 352,344	$ 1,611	$ (3,786)	$ 350,169
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	39,166	0	39,166
Cash dividends declared	0	(13,239)	0	(13,239)
Repurchase of common stock	(13,784)	0	0	(13,784)
Issuance of common stock	11	0	0	11
Share based compensation	1,506	0	0	1,506
Share based compensation withholding obligation	(669)	0	0	(669)
Other comprehensive income (loss)	0	0	9,932	9,932
Balances at end of period at Sep. 30, 2020	339,408	27,538	6,146	373,092
Balance at beginning of period at Jun. 30, 2020	338,989	12,338	3,796	355,123
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	19,584	0	19,584
Cash dividends declared	0	(4,384)	0	(4,384)
Share based compensation	497	0	0	497
Share based compensation withholding obligation	(78)	0	0	(78)
Other comprehensive income (loss)	0	0	2,350	2,350
Balances at end of period at Sep. 30, 2020	339,408	27,538	6,146	373,092
Balance at beginning of period at Dec. 31, 2020	339,353	40,145	10,024	389,522	$ 339,353	$ 29,842	$ 10,024	$ 379,219
Balance at beginning of period (ASU 2016-13 [Member]) at Dec. 31, 2020									$ 0	$ (10,303)	$ 0	$ (10,303)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	50,387	0	50,387
Cash dividends declared	0	(13,686)	0	(13,686)
Repurchase of common stock	(13,773)	0	0	(13,773)
Issuance of common stock	55	0	0	55
Share based compensation	1,446	0	0	1,446
Share based compensation withholding obligation	(691)	0	0	(691)
Other comprehensive income (loss)	0	0	(2,926)	(2,926)
Balances at end of period at Sep. 30, 2021	326,390	66,543	7,098	400,031
Balance at beginning of period at Jun. 30, 2021	332,457	55,101	8,416	395,974
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	15,962	0	15,962
Cash dividends declared	0	(4,520)	0	(4,520)
Repurchase of common stock	(6,488)	0	0	(6,488)
Issuance of common stock	6	0	0	6
Share based compensation	499	0	0	499
Share based compensation withholding obligation	(84)	0	0	(84)
Other comprehensive income (loss)	0	0	(1,318)	(1,318)
Balances at end of period at Sep. 30, 2021	$ 326,390	$ 66,543	$ 7,098	$ 400,031