Investment Securities - Narrative (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022 USD ($) security	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) security	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) security	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Debt and Equity Securities, FV-NI [Line Items]
Accrued interest receivable	$ 39,034,000		$ 39,034,000		$ 38,528,000
Marketable securities at fair value	2,962,000		2,962,000		3,367,000
Trade date receivable - securities			0		0
Net (loss) gain on change in fair value and sale of equity securities	(141,000)	$ (24,000)	(405,000)	$ 188,000
Allowance for credit losses for investments	$ 0		$ 0		$ 0
Number of securities in securities portfolio | security	504		504		511
Number of securities in securities portfolio, unrealized loss position | security	487		487		80
Unrealized loss position	$ 1,476,628,000		$ 1,476,628,000		$ 1,030,914,000
Collateral Pledged
Debt and Equity Securities, FV-NI [Line Items]
Securities pledged	1,213,747,000		1,213,747,000		1,226,646,000
Debt Securities
Debt and Equity Securities, FV-NI [Line Items]
Accrued interest receivable	5,535,000		5,535,000		5,051,000
Increase (decrease) in debt securities, available for sale	(91,104,000)	7,947,000	(263,341,000)	20,178,000
Unrealized loss position	$ 258,614,000		$ 258,614,000
Unrealized gain position		$ (14,374,000)		$ (14,374,000)	$ (4,727,000)	$ (167,510,000)	$ (22,321,000)	$ (34,552,000)