Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Treasury stock	Retained earnings	Accumulated other comprehensive income
Balance, beginning of period (in shares) at Dec. 31, 2020		19,878,713
Balance, beginning of period at Dec. 31, 2020	$ 485,787	$ 2	$ 259,363	$ (38,148)	$ 255,451	$ 9,119
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation, net of forfeitures	1,501		1,501
Net income	34,347				34,347
Other comprehensive income (loss)	(1,714)					(1,714)
Balance, end of period (in shares) at Sep. 30, 2021		19,878,713
Balance, ending of period at Sep. 30, 2021	519,921	$ 2	260,864	(38,148)	289,798	7,405
Balance, beginning of period (in shares) at Jun. 30, 2021		19,878,713
Balance, beginning of period at Jun. 30, 2021	510,582	$ 2	260,516	(38,148)	281,070	7,142
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation, net of forfeitures	348		348
Net income	8,728				8,728
Other comprehensive income (loss)	263					263
Balance, end of period (in shares) at Sep. 30, 2021		19,878,713
Balance, ending of period at Sep. 30, 2021	$ 519,921	$ 2	260,864	(38,148)	289,798	7,405
Balance, beginning of period (in shares) at Dec. 31, 2021	19,903,342	19,903,342
Balance, beginning of period at Dec. 31, 2021	$ 524,038	$ 2	261,905	(38,148)	298,615	1,664
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on restricted stock grants (in shares)		11,344
Issuance of common stock on restricted stock grants	$ 169		169
Stock option exercises (in shares)	67,976	80,934
Stock option exercises	$ (414)		(414)
Share-based compensation, net of forfeitures	924		924
Net income	34,612				34,612
Other comprehensive income (loss)	(44,770)					(44,770)
Merger with Pioneer Bancshares, Inc. (issuance of treasury stock) (in shares)		4,910,412
Merger with Pioneer Bancshares, Inc. (issuance of treasury stock 1,557,054 shares)	$ 236,094		197,946	38,148
Balance, end of period (in shares) at Sep. 30, 2022	24,906,032	24,906,032
Balance, ending of period at Sep. 30, 2022	$ 750,653	$ 2	460,530	0	333,227	(43,106)
Balance, beginning of period (in shares) at Jun. 30, 2022		24,850,954
Balance, beginning of period at Jun. 30, 2022	727,542	$ 2	460,263	0	306,714	(39,437)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on restricted stock grants	102		102
Stock option exercises (in shares)		55,078
Stock option exercises	(206)		(206)
Share-based compensation, net of forfeitures	371		371
Net income	26,513				26,513
Other comprehensive income (loss)	$ (3,669)					(3,669)
Balance, end of period (in shares) at Sep. 30, 2022	24,906,032	24,906,032
Balance, ending of period at Sep. 30, 2022	$ 750,653	$ 2	$ 460,530	$ 0	$ 333,227	$ (43,106)