Financial Instruments (Notational Amounts of Derivatives Held) (Details) $ in Millions	Sep. 30, 2023 USD ($)
Foreign exchange contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 1,277
Interest rate caps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	14,772
Interest rate caps | Subsidiaries
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	5,900
Interest rate swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	750
Sold
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	10,100
Purchase
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 4,700