Capital (Capital Requirements) (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Banking Regulation, Total Capital [Abstract]
Risk-Based Capital, Required	$ 1,120	$ 1,210
Risk-Based Capital, Actual	7,410	7,446
Regulatory Capital, Required	3,453	3,713
Regulatory Capital, Actual	$ 7,410	$ 7,446
Regulatory Capital Ratio, Required	4.00%	4.00%
Regulatory Capital Ratio, Actual	8.58%	8.02%
Leverage Capital, Required	$ 4,317	$ 4,641
Leverage Capital, Actual	$ 11,115	$ 11,169
Leverage ratio - Required	5.00%	5.00%
Leverage Ratio, Actual	12.88%	12.03%