Borrowed Funds (Narrative) (Details) $ in Millions	Jun. 30, 2024 USD ($)
Parent Company | Senior debt
Debt Instrument [Line Items]
Basis adjustments - Fair value accounting hedges	$ (766)
Parent Company | Subordinated debt
Debt Instrument [Line Items]
Basis adjustments - Fair value accounting hedges	(68)
Subsidiaries | Senior debt
Debt Instrument [Line Items]
Basis adjustments - Fair value accounting hedges	(151)
Subsidiaries | Subordinated debt
Debt Instrument [Line Items]
Basis adjustments - Fair value accounting hedges	$ (187)