Regulatory Capital and Reserve Requirements Regulatory Capital and Reserve Requirements (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Dividends available to be paid to parent company without obtaining prior approval from bank regulatory agencies	$ 400
Dividends from bank subsidiaries	$ 675	$ 1,000	$ 852
Total risk-based capital	10.00%	10.00%
Tier 1 Risk-Based Capital	6.00%	6.00%
U.S. Banking Subsidiaries
Total risk-based capital	10.00%	10.00%
Tier 1 Risk-Based Capital	8.00%	8.00%
CET1 risk-based capital	6.50%	6.50%
Leverage ratio	5.00%	5.00%