CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2019	$ 18,036	$ 140,492	$ 146,696	$ 958	$ 306,182
Balance (in shares) at Dec. 31, 2019	18,036,115
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net	$ 0	0	0	0	0
Issuance of common stock, net (in shares)	0
Net income	$ 0	0	12,698	0	12,698
Cash dividends, common	0	0	(1,083)	0	(1,083)
Other comprehensive income (loss), net of tax	0	0	0	18,586	18,586
Exercise of employee stock options and vesting of restricted stock units	$ 28	(157)	0	0	(129)
Exercise of employee stock options and vesting of restricted stock units (in shares)	27,759
Repurchases of common stock	$ (5)	(56)	0	0	(61)
Repurchases of common stock (in shares)	(4,700)
Stock based compensation	$ 0	341	0	0	341
Balance at Jun. 30, 2020	$ 18,059	140,620	158,311	19,544	336,534
Balance (in shares) at Jun. 30, 2020	18,059,174
Balance at Mar. 31, 2020	$ 18,056	140,699	153,238	14,897	326,890
Balance (in shares) at Mar. 31, 2020	18,056,014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net	$ 0	0	0	0	0
Issuance of common stock, net (in shares)	0
Net income	$ 0	0	5,615	0	5,615
Cash dividends, common	0	0	(542)	0	(542)
Other comprehensive income (loss), net of tax	0	0	0	4,647	4,647
Exercise of employee stock options and vesting of restricted stock units	$ 8	(54)	0	0	(46)
Exercise of employee stock options and vesting of restricted stock units (in shares)	7,860
Repurchases of common stock	$ (5)	(56)	0	0	(61)
Repurchases of common stock (in shares)	(4,700)
Stock based compensation	$ 0	31	0	0	31
Balance at Jun. 30, 2020	$ 18,059	140,620	158,311	19,544	336,534
Balance (in shares) at Jun. 30, 2020	18,059,174
Balance at Dec. 31, 2020	$ 18,076	141,112	189,521	21,339	$ 370,048
Balance (in shares) at Dec. 31, 2020	18,076,364				18,076,364
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	0	28,810	0	$ 28,810
Cash dividends, common	0	0	(2,167)	0	(2,167)
Other comprehensive income (loss), net of tax	0	0	0	(2,914)	(2,914)
Exercise of employee stock options and vesting of restricted stock units	$ 21	(127)	0	0	(106)
Exercise of employee stock options and vesting of restricted stock units (in shares)	20,552
Repurchases of common stock	$ (83)	(1,595)	0	0	(1,678)
Repurchases of common stock (in shares)	(82,518)
Stock based compensation	$ 0	822	0	0	822
Balance at Jun. 30, 2021	$ 18,014	140,212	216,164	18,425	$ 392,815
Balance (in shares) at Jun. 30, 2021	18,014,398				18,014,398
Balance at Mar. 31, 2021	$ 18,053	140,633	203,777	12,208	$ 374,671
Balance (in shares) at Mar. 31, 2021	18,053,229
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	0	13,650	0	13,650
Cash dividends, common	0	0	(1,263)	0	(1,263)
Other comprehensive income (loss), net of tax	0	0	0	6,217	6,217
Exercise of employee stock options and vesting of restricted stock units	$ 1	(1)	0	0	0
Exercise of employee stock options and vesting of restricted stock units (in shares)	503
Repurchases of common stock	$ (40)	(852)	0	0	(892)
Repurchases of common stock (in shares)	(39,334)
Stock based compensation	$ 0	432	0	0	432
Balance at Jun. 30, 2021	$ 18,014	$ 140,212	$ 216,164	$ 18,425	$ 392,815
Balance (in shares) at Jun. 30, 2021	18,014,398				18,014,398