Financial Instruments (Notational Amounts of Derivatives Held) (Details) $ in Millions	Mar. 31, 2024 USD ($)
Foreign exchange contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 2,062
Interest rate caps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	15,835
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	10,600
Purchase
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 5,300