FHLB Advances, Other Borrowings and Subordinated Notes - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)	Aug. 29, 2024 CAD ($)	Aug. 28, 2024 CAD ($)	Dec. 31, 2019
Debt Instrument [Line Items]
Secured borrowings		$ 401,863,000	$ 439,513,000	$ 334,934,000
Outstanding subordinated notes		298,536,000	298,188,000	298,283,000
Repayments of subordinated notes		0	140,000,000
Secured Debt
Debt Instrument [Line Items]
Secured borrowings		14,000,000.0	10,900,000	11,700,000
Fixed Rate Promissory Note
Debt Instrument [Line Items]
Principal amount of debt		$ 66,400,000
Stated interest rate		1.40%
Term Loan Facility
Debt Instrument [Line Items]
Amount outstanding		$ 121,400,000
Revolving Credit Facility
Debt Instrument [Line Items]
Amount outstanding		0
Receivables Purchase Agreement | Secured Debt
Debt Instrument [Line Items]
Borrowing capacity					$ 650	$ 520
Secured borrowings		$ 387,900,000	$ 428,600,000	$ 323,200,000
Basis spread on variable rate		0.825%
4.85% subordinated notes maturing in June 2029 | Subordinated Debt
Debt Instrument [Line Items]
Stated interest rate							4.85%
5.00% subordinated notes maturing in June 2024
Debt Instrument [Line Items]
Repayments of subordinated notes	$ 140,000,000
5.00% subordinated notes maturing in June 2024 | Subordinated Debt
Debt Instrument [Line Items]
Stated interest rate	5.00%