Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2019	$ 430,215	$ 205	$ 213,004	$ (22,370)	$ 227,165	$ 12,211
Beginning Balance (ASU 2016-13 [Member]) at Dec. 31, 2019	(594)				(594)
Beginning Balance, Shares at Dec. 31, 2019		20,560,833		(1,258,250)
Comprehensive income:
Net income	58,101				58,101
Other comprehensive income:
Change in unrealized gains (losses), net of tax	7,701					7,701
Comprehensive income	65,802
Unrealized gain (loss) on debt securities, net of tax	7,701					7,701
Common stock issued	1,360	$ 1	1,359
Common stock issued, Shares		28,476
Share-based compensation	777		777
Dividends to shareholders	(15,650)				(15,650)
Ending Balance at Sep. 30, 2020	481,910	$ 206	215,140	$ (22,370)	269,022	19,912
Ending Balance, Shares at Sep. 30, 2020		20,589,309		(1,258,250)
Beginning Balance at Jun. 30, 2020	462,796	$ 206	214,894	$ (22,370)	250,888	19,178
Beginning Balance, Shares at Jun. 30, 2020		20,589,309		(1,258,250)
Comprehensive income:
Net income	23,353				23,353
Other comprehensive income:
Change in unrealized gains (losses), net of tax	734					734
Comprehensive income	24,087
Unrealized gain (loss) on debt securities, net of tax	734					734
Share-based compensation	246		246
Dividends to shareholders	(5,219)				(5,219)
Ending Balance at Sep. 30, 2020	481,910	$ 206	215,140	$ (22,370)	269,022	19,912
Ending Balance, Shares at Sep. 30, 2020		20,589,309		(1,258,250)
Beginning Balance at Dec. 31, 2020	$ 438,816	$ 206	215,316	$ (22,370)	224,645	21,019
Beginning Balance, Shares at Dec. 31, 2020	19,331,059	20,589,309		(1,258,250)
Comprehensive income:
Net income	$ 62,215				62,215
Other comprehensive income:
Change in unrealized gains (losses), net of tax	(6,033)					(6,033)
Comprehensive income	56,182
Unrealized gain (loss) on debt securities, net of tax	(6,033)					(6,033)
Common stock issued	1,563		1,563
Common stock issued, Shares		32,995
Share-based compensation	432		432
Dividends to shareholders	(16,837)				(16,837)
Ending Balance at Sep. 30, 2021	$ 480,156	$ 206	217,311	$ (22,370)	270,023	14,986
Ending Balance, Shares at Sep. 30, 2021	19,364,054	20,622,304		(1,258,250)
Beginning Balance at Jun. 30, 2021	$ 468,366	$ 206	217,165	$ (22,370)	256,503	16,862
Beginning Balance, Shares at Jun. 30, 2021		20,622,304		(1,258,250)
Comprehensive income:
Net income	19,136				19,136
Other comprehensive income:
Change in unrealized gains (losses), net of tax	(1,876)					(1,876)
Comprehensive income	17,260
Unrealized gain (loss) on debt securities, net of tax	(1,876)					(1,876)
Share-based compensation	146		146
Dividends to shareholders	(5,616)				(5,616)
Ending Balance at Sep. 30, 2021	$ 480,156	$ 206	$ 217,311	$ (22,370)	$ 270,023	$ 14,986
Ending Balance, Shares at Sep. 30, 2021	19,364,054	20,622,304		(1,258,250)