Loans and Allowance for Credit Losses - Purchased Credit Deteriorated Loans (Details) - USD ($) $ in Thousands			3 Months Ended
	May 01, 2025	Apr. 01, 2024	Jun. 30, 2025
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchase price of loans at acquisition		$ 610,700
Allowance for credit losses at acquisition		26,700
Par value of acquired loans at acquisition		679,300
Bremer
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchase price of loans at acquisition	$ 1,900,000	1,889,330
Allowance for credit losses at acquisition	90,400	90,442	$ 90,400
Non-credit discount at acquisition		75,817
Par value of acquired loans at acquisition	$ 2,100,000	2,055,589
CapStar Financial Holdings, Inc.
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchase price of loans at acquisition		610,691
Allowance for credit losses at acquisition		26,725
Non-credit discount at acquisition		41,886
Par value of acquired loans at acquisition		$ 679,302