Investment Securities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Federal Reserve and Federal Home Loan Bank stock	$ 25,689			$ 25,689		$ 65,067
Transfers from loans to other real estate owned				0	$ 475
Payments to acquire held-to-maturity securities				0	290,740
Realized gain recognized at time of transfer				0
Accrued interest on HTM securities	3,600			3,600		3,500
Allowance for credit losses for held-to-maturity securities in the period				(1,200)
Allowance for credit losses	17			17		17
HTM Allowance for credit losses	$ 2,010			$ 2,010		$ 766
Debt securities as percentage of total investment securities	100.00%			100.00%
Debt securities weighted average duration				4 years 7 months 2 days
Debt securities, available-for-sale, realized gain	$ 5	$ 4		$ 126	16
Debt securities, available-for-sale, realized loss	0			(140)	187
Gross proceeds from sales and calls	$ 2,600	$ 6,200		$ 11,200	$ 26,200
Holdings of securities of any one issuer	10.00%			10.00%		10.00%
Collateral Pledged
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, restricted	$ 2,300,000			$ 2,300,000		$ 220,100
Other Assets
Debt Securities, Available-for-sale [Line Items]
Accrued interest on available for sale securities	4,000			4,000		4,300
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Transfers from loans to other real estate owned			$ 1,100,000
Payments to acquire held-to-maturity securities			237,000
Unrealized loss			$ 66,200	53,500
Allowance for credit losses	0			0		0
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Allowance for credit losses	0			0		0
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Allowance for credit losses	$ 17			$ 17		$ 17