Loans and Allowance for Credit Losses - PCD Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Non-credit related discount	$ (26,400)	$ (21,500)
Spirit of Texas Bancshares, Inc.
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	74,851
PCD allowance for credit loss at acquisition	(9,622)
Non-credit related discount	(1,377)
Fair value of PCD loans	63,852
Spirit of Texas Bancshares, Inc. | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	8,258
PCD allowance for credit loss at acquisition	(6,433)
Non-credit related discount	(378)
Fair value of PCD loans	1,447
Spirit of Texas Bancshares, Inc. | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	66,534
PCD allowance for credit loss at acquisition	(3,187)
Non-credit related discount	(998)
Fair value of PCD loans	62,349
Spirit of Texas Bancshares, Inc. | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	0
PCD allowance for credit loss at acquisition	0
Non-credit related discount	0
Fair value of PCD loans	0
Spirit of Texas Bancshares, Inc. | Other Consumer and Other
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	59
PCD allowance for credit loss at acquisition	(2)
Non-credit related discount	(1)
Fair value of PCD loans	56
Landmark Bank
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	66,662
PCD allowance for credit loss at acquisition	(2,359)
Non-credit related discount	(2,577)
Fair value of PCD loans	61,726
Landmark Bank | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	11,046
PCD allowance for credit loss at acquisition	(350)
Non-credit related discount	(160)
Fair value of PCD loans	10,536
Landmark Bank | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	55,549
PCD allowance for credit loss at acquisition	(2,008)
Non-credit related discount	(2,415)
Fair value of PCD loans	51,126
Landmark Bank | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	0
PCD allowance for credit loss at acquisition	0
Non-credit related discount	0
Fair value of PCD loans	0
Landmark Bank | Other Consumer and Other
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	67
PCD allowance for credit loss at acquisition	(1)
Non-credit related discount	(2)
Fair value of PCD loans	64
Triumph
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	121,284
PCD allowance for credit loss at acquisition	(11,092)
Non-credit related discount	(1,594)
Fair value of PCD loans	108,598
Triumph | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	40,466
PCD allowance for credit loss at acquisition	(2,999)
Non-credit related discount	(279)
Fair value of PCD loans	37,188
Triumph | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	80,803
PCD allowance for credit loss at acquisition	(8,093)
Non-credit related discount	(1,314)
Fair value of PCD loans	71,396
Triumph | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	0
PCD allowance for credit loss at acquisition	0
Non-credit related discount	0
Fair value of PCD loans	0
Triumph | Other Consumer and Other
Financing Receivable, Credit Quality Indicator [Line Items]
Unpaid principal balance	15
PCD allowance for credit loss at acquisition	0
Non-credit related discount	(1)
Fair value of PCD loans	$ 14