Acquisitions- Textual (Details)			9 Months Ended
	Nov. 19, 2021 USD ($) branch shares	Oct. 08, 2021 USD ($) branch shares	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)	Nov. 20, 2021 USD ($)
Business Acquisition [Line Items]
Stock issued for acquisition			$ 464,918,000
Goodwill			$ 1,309,000,000	$ 1,146,007,000
Spirit of Texas Bancshares, Inc.
Business Acquisition [Line Items]
Shares issued (in shares) | shares	18,275,074
Payments to acquire businesses, gross	$ 464,900,000
Stock issued for acquisition	$ 1,393,508,900
Number of bank branches acquired | branch	35
Assets acquired, after acquisition method adjustments	$ 3,120,000,000
Loans acquired, after acquisition method adjustments	2,290,000,000
Customer deposits acquired, after acquisition method adjustments	2,720,000,000
Goodwill	162,300,000				$ 162,347,000
Assets acquired	3,200,312,000				3,118,149,000
Loans acquired	2,314,085,000				2,294,160,000
Deposits acquired	$ 2,718,100,000				$ 2,719,016,000
Landmark Community Bank
Business Acquisition [Line Items]
Shares issued (in shares) | shares		4,499,872
Payments to acquire businesses, gross		$ 138,200,000
Stock issued for acquisition		$ 6,451,727,430
Number of bank branches acquired | branch		8
Goodwill		$ 31,400,000
Assets acquired		968,800,000
Loans acquired		789,500,000
Deposits acquired		$ 802,700,000
Triumph Bancshares
Business Acquisition [Line Items]
Shares issued (in shares) | shares		4,164,712
Payments to acquire businesses, gross		$ 127,900,000
Stock issued for acquisition		$ 1,693,402,930
Number of bank branches acquired | branch		6
Goodwill		$ 39,900,000
Assets acquired		847,200,000
Loans acquired		698,800,000
Deposits acquired		$ 719,700,000