Borrowings - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Balance	$ 1,528,695,000	$ 1,127,047,000
Unused line of credit	339,000,000	339,000,000
Advances from federal home loan banks	$ 3,600,000,000	$ 1,600,000,000
Weighted average interest rate (as a percent)	4.94%	4.36%
Proceeds from long-term borrowings	$ 536,113,000	$ 335,893,000	$ 37,120,000
Subsidiaries
Debt Instrument [Line Items]
Advances from federal home loan banks	29,100,000	35,000,000
Line of Credit
Debt Instrument [Line Items]
Balance	0	0
Interest expense, debt	923,000	1,900,000	7,000
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest expense, debt	95,000	122,000
Line of credit facility, maximum borrowing capacity			30,000,000
Proceeds from long-term borrowings	1,500,000	6,500,000
Repayments of long-term debt	1,500,000	6,500,000
Securities sold under agreements to repurchase
Debt Instrument [Line Items]
Advances from federal home loan banks	16,400,000	87,700,000
Securities sold under agreements to repurchase | Subsidiaries
Debt Instrument [Line Items]
Advances from federal home loan banks	43,100,000	27,600,000
FHLB advances
Debt Instrument [Line Items]
Balance	1,521,733,000	1,090,159,000
Interest expense, debt	$ 61,500,000	$ 11,500,000	7,600,000
Weighted average interest rate (as a percent)	4.92%	4.37%
Notes payable
Debt Instrument [Line Items]
Balance	$ 0	$ 29,894,000
Interest expense, debt	$ 823,000	$ 1,100,000
Debt instrument, face amount			$ 30,000,000
Weighted average interest rate (as a percent)	0.00%	3.35%	3.35%
Junior subordinated debentures
Debt Instrument [Line Items]
Balance	$ 6,962,000	$ 6,994,000
Interest expense, debt	$ 624,000	$ 370,000	$ 245,000
Weighted average interest rate (as a percent)	8.59%	7.69%
Interest rate, effective percentage	8.59%	7.69%
Interest Rate Swap | FHLB advances
Debt Instrument [Line Items]
Notional amount of derivative	$ 380,000,000	$ 290,000,000
Secured Overnight Financing Rate (SOFR) | Junior subordinated debentures
Debt Instrument [Line Items]
Basis spread on variable rate	2.95%