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		9 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Interest rate contracts | Fair Value Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain/(Loss) Recognized in Earnings	$ (2)	$ (7)	$ 109	$ 122
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	$ 30	$ (84)	$ (19)	$ (27)