Risk Management Activities and Fair Value Measurements - Gains And Losses On Derivatives In Net Investment Hedges Recognized in Earnings (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Interest rate contracts | Fair Value Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain/(Loss) Recognized in Earnings	$ 6	$ 76
Foreign currency interest rate contracts | Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain/(Loss) Recognized in Earnings	$ (6)	$ 126