Investment Securities - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) security	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) security	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) security
Debt and Equity Securities, FV-NI [Line Items]
Accrued interest receivable	$ 49,205,000		$ 49,205,000		$ 45,684,000
Trade date receivable - securities	789,000	$ 0	789,000	$ 0	0
Trade date payable - securities	10,930,000	0	10,930,000	0	0
Allowance for credit losses for investments	$ 0		$ 0		$ 0
Number of securities in securities portfolio | security	472		472		503
Number of securities in securities portfolio, unrealized loss position | security	464		464		454
Marketable securities at fair value	$ 2,934,000		$ 2,934,000		$ 2,990,000
Equity securities without readily determinable market value	24,487,000		24,487,000		22,496,000
Federal Home Loan Bank stock, at cost	34,809,000		34,809,000		58,641,000
Net (loss) gain on change in fair value and sale of equity securities	(97,000)	$ (141,000)	(56,000)	$ (405,000)
Collateral Pledged
Debt and Equity Securities, FV-NI [Line Items]
Securities pledged	853,637,000		853,637,000		1,191,021,000
Debt Securities
Debt and Equity Securities, FV-NI [Line Items]
Accrued interest receivable	$ 5,159,000		$ 5,159,000		$ 5,470,000