Commitments and Contingencies (Narrative) (Details) - USD ($)	3 Months Ended		13 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Nov. 30, 2024	Mar. 31, 2023	Dec. 31, 2022
Other Commitments [Line Items]
Reserve for unfunded lending commitments	$ 27,063,000	$ 28,894,000		$ 32,014,000	$ 33,309,000
Federal Deposit Insurance Corporation (FDIC) Special Assessment [Member]
Other Commitments [Line Items]
Pre-tax special assessment expense		$ 26,100,000
Additional special assessment expense	3,800,000
Federal Deposit Insurance Corporation (FDIC) Special Assessment [Member] | Silicon Valley Bank and Signature Bank [Member]
Other Commitments [Line Items]
Increase in estimated losses attributable to protection of uninsured depositors	4,100,000,000
Estimated losses attributable to protection of uninsured depositors	$ 20,400,000,000		$ 16,300,000,000