Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated Other Comprehensive Loss	Treasury stock
Common shares outstanding at Dec. 31, 2019		8,566,044
Beginning balance at Dec. 31, 2019	$ 194,156	$ 92	$ 81,188	$ 129,105	$ (1,348)	$ (14,881)
Net income	3,278			3,278
Other comprehensive income (loss)	663				663
Share-based compensation - restricted shares	417	0	417
Cash Dividends	(1,410)			(1,410)
Treasury stock purchased	(1,447)					(1,447)
Ending balance at Mar. 31, 2020	195,657	$ 92	81,605	130,973	(685)	(16,328)
Common shares outstanding at Mar. 31, 2020		8,571,134
Share-based compensation - restricted shares, shares issued		63,684
Treasury stock purchased, shares		(58,594)
Common shares outstanding at Dec. 31, 2019		8,566,044
Beginning balance at Dec. 31, 2019	194,156	$ 92	81,188	129,105	(1,348)	(14,881)
Net income	6,601
Ending balance at Jun. 30, 2020	197,562	$ 92	82,121	132,882	(1,186)	(16,347)
Common shares outstanding at Jun. 30, 2020		8,575,134
Common shares outstanding at Mar. 31, 2020		8,571,134
Beginning balance at Mar. 31, 2020	195,657	$ 92	81,605	130,973	(685)	(16,328)
Net income	3,323			3,323
Other comprehensive income (loss)	(501)				(501)
Share-based compensation - restricted shares	516	0	516
Cash Dividends	(1,414)			(1,414)
Treasury stock purchased	(19)					(19)
Ending balance at Jun. 30, 2020	$ 197,562	$ 92	82,121	132,882	(1,186)	(16,347)
Common shares outstanding at Jun. 30, 2020		8,575,134
Share-based compensation - restricted shares, shares issued		5,357
Treasury stock purchased, shares		(1,357)
Common shares outstanding at Dec. 31, 2020	8,566,960	8,566,960
Beginning balance at Dec. 31, 2020	$ 206,162	$ 92	83,125	140,431	(933)	(16,553)
Net income	9,731			9,731
Other comprehensive income (loss)	(105)				(105)
Share-based compensation - restricted shares	531	1	530
Issuance of common stock under the employee stock purchase plan	39		39
Cash Dividends	(1,541)			(1,541)
Treasury stock purchased	(326)					(326)
Ending balance at Mar. 31, 2021	$ 214,491	$ 93	83,694	148,621	(1,038)	(16,879)
Common shares outstanding at Mar. 31, 2021		8,638,195
Share-based compensation - restricted shares, shares issued		84,255
Issuance of common stock under the employee stock purchase plan, shares		1,775
Treasury stock purchased, shares		(14,795)
Common shares outstanding at Dec. 31, 2020	8,566,960	8,566,960
Beginning balance at Dec. 31, 2020	$ 206,162	$ 92	83,125	140,431	(933)	(16,553)
Net income	17,966
Ending balance at Jun. 30, 2021	$ 221,452	$ 93	84,343	155,300	(763)	(17,521)
Common shares outstanding at Jun. 30, 2021	8,617,761	8,617,761
Issuance of common stock under the employee stock purchase plan, shares	3,469
Common shares outstanding at Mar. 31, 2021		8,638,195
Beginning balance at Mar. 31, 2021	$ 214,491	$ 93	83,694	148,621	(1,038)	(16,879)
Net income	8,235			8,235
Other comprehensive income (loss)	275				275
Share-based compensation - restricted shares	607	0	607
Issuance of common stock under the employee stock purchase plan	42		42
Cash Dividends	(1,556)			(1,556)
Treasury stock purchased	(642)					(642)
Ending balance at Jun. 30, 2021	$ 221,452	$ 93	$ 84,343	$ 155,300	$ (763)	$ (17,521)
Common shares outstanding at Jun. 30, 2021	8,617,761	8,617,761
Share-based compensation - restricted shares, shares issued		1,421
Issuance of common stock under the employee stock purchase plan, shares		1,694
Treasury stock purchased, shares		(23,549)