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		6 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2025	Dec. 31, 2024
Interest rate contracts | Fair Value Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain/(Loss) Recognized in Earnings	$ (12)	$ 34	$ (5)	$ 110
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	$ 28	$ (174)	$ 22	$ (48)