Financial Instruments (Notational Amounts of Derivatives Held) (Details) $ in Millions	Mar. 31, 2025 USD ($)
Foreign exchange contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 1,617
Interest rate caps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	9,466
Interest rate caps | Subsidiaries
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	3,200
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	6,200
Purchase
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 3,200