Commitments (Narrative) (Details) $ in Billions	3 Months Ended
	Mar. 31, 2024 USD ($)
Minimum
Loss Contingencies [Line Items]
Standby letter of credit, term (less than one year)	1 year
Maximum
Loss Contingencies [Line Items]
Standby letter of credit, term (less than one year)	7 years
Standby letters of credit
Loss Contingencies [Line Items]
Internal credit ratings (as a percentage of portfolio) - Pass	97.00%
Standby letters of credit - Assets securing certain specifically identified standby letters of credit	$ 1.1
Standby letters of credit and participations in standby letters of credit - Liability carrying amount	$ 0.2