Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Nov. 20, 2021	Oct. 08, 2021	Dec. 31, 2022	Dec. 31, 2021	Nov. 19, 2021	Oct. 07, 2021
Assets Acquired
Goodwill			$ 1,319,598	$ 1,146,007
Spirit of Texas Bancshares, Inc.
Assets Acquired
Cash and due from banks	$ 277,790				$ 277,790
Investment securities	348,687				362,088
Loans acquired	2,294,160				2,314,085
Allowance for credit losses on loans	(9,623)				(17,005)
Premises and equipment	65,061				84,135
Bank owned life insurance	36,890				36,890
Goodwill	0				77,681
Other assets	55,955				58,403
Total assets acquired	3,107,551				3,200,312
Liabilities Assumed
Noninterest bearing transaction accounts	825,063				825,228
Interest bearing transaction accounts and savings deposits	1,383,663				1,383,663
Time deposits	510,290				509,209
Total deposits	2,719,016				2,718,100
Other borrowings	38,050				37,547
Subordinated debentures	37,370				36,491
Accrued interest and other liabilities	19,749				23,667
Total liabilities assumed	2,814,185				2,815,805
Equity	0				384,507
Total liabilities and equity assumed	2,814,185				3,200,312
Net assets acquired	293,366
Purchase price	466,311
Goodwill acquired	172,945
Spirit of Texas Bancshares, Inc. | Fair Value Adjustments
Assets Acquired
Cash and due from banks	0
Investment securities	(13,401)
Loans acquired	(19,925)
Allowance for credit losses on loans	7,382
Premises and equipment	(19,074)
Bank owned life insurance	0
Goodwill	(77,681)
Other assets	(2,448)
Total assets acquired	(92,761)
Liabilities Assumed
Noninterest bearing transaction accounts	(165)
Interest bearing transaction accounts and savings deposits	0
Time deposits	1,081
Total deposits	916
Other borrowings	503
Subordinated debentures	879
Accrued interest and other liabilities	(3,918)
Total liabilities assumed	(1,620)
Equity	(384,507)
Total liabilities and equity assumed	(386,127)
Landmark Community Bank
Assets Acquired
Cash and due from banks		$ 27,591				$ 27,591
Due from banks - time		100				100
Investment securities		114,668				114,793
Loans acquired		789,504				785,551
Allowance for credit losses on loans		(2,359)				(5,980)
Premises and equipment		5,441				9,540
Bank owned life insurance		21,287				21,287
Goodwill		31,404
Other assets		8,431				13,036
Total assets acquired		968,822				966,006
Liabilities Assumed
Noninterest bearing transaction accounts		110,393				110,393
Interest bearing transaction accounts and savings deposits		425,777				425,777
Time deposits		266,501				266,835
Total deposits		802,671				803,005
Other borrowings		47,023				47,023
Accrued interest and other liabilities		5,337				8,459
Total liabilities assumed		855,031				858,487
Equity		0				107,519
Total liabilities and equity assumed		855,031				966,006
Net assets acquired		113,791
Purchase price		145,195
Landmark Community Bank | Fair Value Adjustments
Assets Acquired
Cash and due from banks		0
Due from banks - time		0
Investment securities		(125)
Loans acquired		3,953
Allowance for credit losses on loans		3,621
Premises and equipment		(4,099)
Bank owned life insurance		0
Other assets		(4,605)
Total assets acquired		2,816
Liabilities Assumed
Noninterest bearing transaction accounts		0
Interest bearing transaction accounts and savings deposits		0
Time deposits		(334)
Total deposits		(334)
Other borrowings		0
Accrued interest and other liabilities		(3,122)
Total liabilities assumed		(3,456)
Equity		(107,519)
Total liabilities and equity assumed		(110,975)
Triumph Bancshares, Inc.
Assets Acquired
Cash and due from banks		7,484				7,484
Due from banks - time		495				495
Investment securities		129,455				130,571
Loans acquired		698,786				702,460
Allowance for credit losses on loans		(11,092)				(12,617)
Premises and equipment		3,258				2,774
Goodwill		0				1,550
Other assets		13,703				12,806
Total assets acquired		847,225				845,523
Liabilities Assumed
Noninterest bearing transaction accounts		115,729				115,729
Interest bearing transaction accounts and savings deposits		383,434				383,434
Time deposits		220,571				219,477
Total deposits		719,734				718,640
Other borrowings		2,854				2,854
Subordinated debentures		30,700				30,700
Accrued interest and other liabilities		3,337				2,882
Total liabilities assumed		756,625				755,076
Equity		0				90,446
Total liabilities and equity assumed		756,625				845,522
Net assets acquired		90,600
Purchase price		130,544
Goodwill acquired		39,944
Triumph Bancshares, Inc. | Fair Value Adjustments
Assets Acquired
Cash and due from banks		0
Due from banks - time		0
Investment securities		(1,116)
Loans acquired		(3,674)
Allowance for credit losses on loans		1,525
Premises and equipment		484
Goodwill		(1,550)
Other assets		897
Total assets acquired		1,702
Liabilities Assumed
Noninterest bearing transaction accounts		0
Interest bearing transaction accounts and savings deposits		0
Time deposits		1,094
Total deposits		1,094
Other borrowings		0
Subordinated debentures		0
Accrued interest and other liabilities		455
Total liabilities assumed		1,549
Equity		(90,446)
Total liabilities and equity assumed		(88,897)
Core Deposit Premium | Spirit of Texas Bancshares, Inc.
Assets Acquired
Core deposit and other intangible assets	38,631				$ 6,245
Core Deposit Premium | Spirit of Texas Bancshares, Inc. | Fair Value Adjustments
Assets Acquired
Core deposit and other intangible assets	$ 32,386
Core Deposit Premium | Landmark Community Bank
Assets Acquired
Core deposit and other intangible assets		4,159				88
Core Deposit Premium | Landmark Community Bank | Fair Value Adjustments
Assets Acquired
Core deposit and other intangible assets		4,071
Core Deposit Premium | Triumph Bancshares, Inc.
Assets Acquired
Core deposit and other intangible assets		5,136				$ 0
Core Deposit Premium | Triumph Bancshares, Inc. | Fair Value Adjustments
Assets Acquired
Core deposit and other intangible assets		$ 5,136