Derivatives (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) contracts	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) contracts	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) contracts
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Counterparty default losses on forward contracts	$ 0	$ 0	$ 0	$ 0
Credit Derivatives [Line Items]
Commitments
Collateralized financings	4,200		4,200
Termination value of derivatives in a net liability position	401,500		401,500		270,000
Collateral required to be posted under agreements	82,100		82,100		89,500
Variation Margin Adjustment	$ 261,700		$ 261,700		$ 209,500
Customer swaps offset by a swap executed on a bilateral basis with a counterparty bank	228		228		71
Counterparty bank cash as collateral on bilateral positions	$ 149,700		$ 149,700		$ 51,900
Interest rate futures
Credit Derivatives [Line Items]
Derivative, notional amount	133,000		133,000
Mortgage-Backed Security
Credit Derivatives [Line Items]
Derivative, notional amount	6,000		6,000
Interest rate swaps
Credit Derivatives [Line Items]
Derivative, notional amount	$ 9,000,000		$ 9,000,000		$ 7,300,000
Number of interest rate swaps | contracts	1,304		1,304		922
Commitments To Originate Loans Held For Sale
Credit Derivatives [Line Items]
Commitments	$ 34,759		$ 34,759		$ 56,100
Interest rate forward sales commitments
Credit Derivatives [Line Items]
Commitments	$ 49,180		$ 49,180		$ 104,000