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, 2024	Dec. 31, 2023	Dec. 31, 2024	Dec. 31, 2023
Interest rate contracts \| Fair Value Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain/(Loss) Recognized in Earnings	$ 34	$ 117	$ 110	$ 128
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	$ (174)	$ 128	$ (48)	$ 57

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration