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	67					67
Stock option exercises (in shares)				25,856
Stock option exercises	(208)					(208)
Share-based compensation, net of forfeitures	553					553
Net income	8,099									8,099
Other comprehensive income	(41,101)												(41,101)
Balance, end of period (in shares) at Jun. 30, 2022				24,850,954
Balance, ending of period at Jun. 30, 2022	727,542			$ 2		460,263		0		306,714			(39,437)
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
Balance, end of period (in shares) at Dec. 31, 2022	24,920,984			24,920,984	24,920,984
Balance, ending 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]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2016-13
Balance, beginning of period (in shares) at Mar. 31, 2022				19,903,342
Balance, beginning of period at Mar. 31, 2022	$ 515,541			$ 2		262,071		(38,148)		306,284			(14,668)
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	67					67
Stock option exercises (in shares)				25,856
Stock option exercises	(208)					(208)
Share-based compensation, net of forfeitures	387					387
Net income	430									430
Other comprehensive income	(24,769)												(24,769)
Balance, end of period (in shares) at Jun. 30, 2022				24,850,954
Balance, ending of period at Jun. 30, 2022	$ 727,542			$ 2		460,263		0		306,714			(39,437)
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	202					202
Stock option exercises (in shares)				5,477
Stock option exercises	53					53
Share-based compensation, net of forfeitures	881					881
Net income	54,287									54,287
Other comprehensive income	$ (2,516)												(2,516)
Balance, end of period (in shares) at Jun. 30, 2023	24,941,468			24,941,468
Balance, ending of period at Jun. 30, 2023	$ 823,635			$ 2		461,856		0		408,276			(46,499)
Balance, beginning of period (in shares) at Mar. 31, 2023				24,924,023
Balance, beginning of period at Mar. 31, 2023	799,050			$ 2		461,174		0		380,270			(42,396)
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	68					68
Stock option exercises (in shares)				2,438
Stock option exercises	25					25
Share-based compensation, net of forfeitures	589					589
Net income	28,006									28,006
Other comprehensive income	$ (4,103)												(4,103)
Balance, end of period (in shares) at Jun. 30, 2023	24,941,468			24,941,468
Balance, ending of period at Jun. 30, 2023	$ 823,635			$ 2		$ 461,856		$ 0		$ 408,276			$ (46,499)