Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative effect of accounting change (Note 1)	Adjusted beginning balance	Common stock	Common stock Adjusted beginning balance	Additional paid-in capital	Additional paid-in capital Adjusted beginning balance	Treasury stock	Treasury stock Adjusted beginning balance	Retained earnings	Retained earnings Cumulative effect of accounting change (Note 1)	Retained earnings Adjusted beginning balance	Accumulated other comprehensive income (loss)	Accumulated other comprehensive income (loss) Adjusted beginning balance
Balance, beginning of period (in shares) at Dec. 31, 2021				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]
Merger with Pioneer Bancshares, Inc. (issuance of treasury stock shares) (in shares)				4,910,412
Merger with Pioneer Bancshares, Inc. (issuance of treasury stock 1,557,054 shares)	236,094					197,946		38,148
Issuance of common stock on restricted stock grants (in shares)				11,344
Issuance of common stock on restricted stock grants (15,007 shares in the second quarter of 2023)	169					169
Stock option exercises (in shares)				80,934
Stock option exercises	(414)					(414)
Share-based compensation, net of forfeitures	924					924
Net income	34,612									34,612
Other comprehensive (loss) income	(44,770)												(44,770)
Balance, end of period (in shares) at Sep. 30, 2022				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 (15,007 shares in the second quarter of 2023)	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 (loss) income	(3,669)												(3,669)
Balance, end of period (in shares) at Sep. 30, 2022				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 Dec. 31, 2022	24,920,984			24,920,984	24,920,984
Balance, beginning of period at Dec. 31, 2022	$ 774,536	$ (3,808)	$ 770,728	$ 2	$ 2	460,720	$ 460,720	0	$ 0	357,797	$ (3,808)	$ 353,989	(43,983)	$ (43,983)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on restricted stock grants (in shares)				15,007
Issuance of common stock on restricted stock grants (15,007 shares in the second quarter of 2023)	304					304
Stock option exercises (in shares)				6,654
Stock option exercises	44					44
Share-based compensation, net of forfeitures	1,439					1,439
Net income	79,519									79,519
Other comprehensive (loss) income	$ (8,315)												(8,315)
Balance, end of period (in shares) at Sep. 30, 2023	24,942,645			24,942,645
Balance, ending of period at Sep. 30, 2023	$ 843,719			$ 2		462,507		0		433,508			(52,298)
Balance, beginning of period (in shares) at Jun. 30, 2023				24,941,468
Balance, beginning of period at Jun. 30, 2023	823,635			$ 2		461,856		0		408,276			(46,499)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on restricted stock grants (15,007 shares in the second quarter of 2023)	102					102
Stock option exercises (in shares)				1,177
Stock option exercises	(9)					(9)
Share-based compensation, net of forfeitures	558					558
Net income	25,232									25,232
Other comprehensive (loss) income	$ (5,799)												(5,799)
Balance, end of period (in shares) at Sep. 30, 2023	24,942,645			24,942,645
Balance, ending of period at Sep. 30, 2023	$ 843,719			$ 2		$ 462,507		$ 0		$ 433,508			$ (52,298)