Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Cumulative Effect, Period of Adoption, Adjustment [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] AOCI Attributable to Parent [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]		Total
Balance (in shares) at Dec. 31, 2018						22,749
Balance at Dec. 31, 2018						$ 36,689	$ 36,797	$ 298,156	$ (5,142)		$ 366,500
Net income						0	0	15,641	0		15,641
Other comprehensive income						0	0	0	2,629		2,629
Stock compensation expense						$ 0	863	0	0		863
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations (in shares)						74
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations						$ 245	2,254	(4,452)	0		(1,953)
Cash dividends declared						0	0	(5,686)	0		(5,686)
Other comprehensive income						$ 0	0	0	2,629		2,629
Balance (in shares) at Mar. 31, 2019						22,823
Balance at Mar. 31, 2019						$ 36,934	39,914	303,659	(2,513)		377,994
Balance (in shares) at Dec. 31, 2018						22,749
Balance at Dec. 31, 2018						$ 36,689	36,797	298,156	(5,142)		366,500
Net income											49,418
Other comprehensive income									6,870		6,870
Other comprehensive income									6,870		6,870
Balance (in shares) at Sep. 30, 2019						22,597
Balance at Sep. 30, 2019						$ 36,184	34,607	323,592	1,728		396,111
Balance (in shares) at Mar. 31, 2019						22,823
Balance at Mar. 31, 2019						$ 36,934	39,914	303,659	(2,513)		377,994
Net income						0	0	16,543	0		16,543
Other comprehensive income						0	0	0	3,579		3,579
Stock compensation expense						$ 0	993	0	0		993
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations (in shares)						5
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations						$ 19	182	(363)	0		(162)
Cash dividends declared						$ 0	0	(5,917)	0		(5,917)
Common stock repurchased (in shares)						(107)
Common stock repurchased						$ (357)	(3,308)	0	0		(3,665)
Shares cancelled						0	(5)	5	0		0
Other comprehensive income						0	0	0	3,579		3,579
Shares cancelled						$ 0	5	(5)	0		0
Balance (in shares) at Jun. 30, 2019						22,721
Balance at Jun. 30, 2019						$ 36,596	37,776	313,927	1,066		389,365
Net income						0	0	17,234	0		17,234
Other comprehensive income						0	0	0	662		662
Stock compensation expense						$ 0	876	0	0		876
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations (in shares)						29
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations						$ 97	994	(1,744)	0		(653)
Cash dividends declared						$ 0	0	(5,874)	0		(5,874)
Common stock repurchased (in shares)						(152)
Common stock repurchased						$ (504)	(4,995)	0	0		(5,499)
Shares cancelled						(5)	(44)	49	0		0
Other comprehensive income						$ 0	0	0	662		662
Shares cancelled (in shares)						(1)
Shares cancelled						$ 5	44	(49)	0		0
Balance (in shares) at Sep. 30, 2019						22,597
Balance at Sep. 30, 2019						$ 36,184	34,607	323,592	1,728		396,111
Balance (in shares) at Dec. 31, 2019						22,604
Balance at Dec. 31, 2019	$ 0	$ 0	$ (8,823)	$ 0	$ (8,823)	$ 36,207	35,714	333,699	677		406,297
Net income						0	0	13,232	0		13,232
Other comprehensive income						0	0	0	5,775		5,775
Stock compensation expense						$ 0	817	0	0		817
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations (in shares)						62
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations						$ 203	1,858	(3,546)	0		(1,485)
Cash dividends declared						0	0	(6,111)	0		(6,111)
Shares cancelled						(2)	(22)	24	0		0
Other comprehensive income						$ 0	0	0	5,775		5,775
Shares cancelled (in shares)						(1)
Shares cancelled						$ 2	22	(24)	0		0
Balance (in shares) at Mar. 31, 2020						22,665
Balance at Mar. 31, 2020						$ 36,408	38,367	328,475	6,452		409,702
Balance (in shares) at Dec. 31, 2019						22,604
Balance at Dec. 31, 2019	$ 0	$ 0	$ (8,823)	$ 0	$ (8,823)	$ 36,207	35,714	333,699	677		406,297
Net income											41,133
Other comprehensive income											8,194
Other comprehensive income											8,194
Balance (in shares) at Sep. 30, 2020						22,692
Balance at Sep. 30, 2020						$ 36,500	41,256	341,970	8,872	[1]	428,598
Balance (in shares) at Mar. 31, 2020						22,665
Balance at Mar. 31, 2020						$ 36,408	38,367	328,475	6,452		409,702
Net income						0	0	13,368	0		13,368
Other comprehensive income						0	0	0	2,364		2,364
Stock compensation expense						$ 0	976	0	0		976
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations (in shares)						2
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations						$ 8	96	(163)	0		(59)
Cash dividends declared						0	0	(6,120)	0		(6,120)
Shares cancelled						(1)	(14)	15	0		0
Other comprehensive income						$ 0	0	0	2,364		2,364
Shares cancelled (in shares)						0
Shares cancelled						$ 1	14	(15)	0		0
Balance (in shares) at Jun. 30, 2020						22,667
Balance at Jun. 30, 2020						$ 36,415	39,425	335,575	8,816		420,231
Net income						0	0	14,533	0		14,533
Other comprehensive income						0	0	0	56		56
Stock compensation expense						$ 0	843	0	0		843
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations (in shares)						27
Stock issued for share-based awards, net of witholdings to satisfy employee tax obligations						$ 91	1,049	(2,083)	0		(943)
Cash dividends declared						0	0	(6,122)	0		(6,122)
Shares cancelled						6	61	(67)	(0)		(0)
Other comprehensive income						$ 0	0	0	56		56
Shares cancelled (in shares)						(2)
Shares cancelled						$ (6)	(61)	67	0		0
Balance (in shares) at Sep. 30, 2020						22,692
Balance at Sep. 30, 2020						$ 36,500	$ 41,256	$ 341,970	$ 8,872	[1]	$ 428,598

[1] December 31, 2017 AOCI component balances reflect a correction of incorrectly reported year-end balances in the Footnote titled "Other Comprehensive Income (Loss)" of the 2017 Form 10-K, which were presented as $(2,278), $234, and $(392) for securities AFS, cash flow hedges, and minimum pension liability, respectively.