Summary of Changes in Accumulated Other Comprehensive Income (Loss) by Component (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2024	Dec. 31, 2023
Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses), net of tax	$ (13)	$ 10	$ (6)	$ 6
Net change related to other comprehensive income (loss), tax	9	(1)	6	5
Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses), net of tax	(121)	352	176	277
Net change related to other comprehensive income (loss), tax	(116)	353	180	284
Translation adjustments and other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net change related to other comprehensive income (loss), tax	$ 0	$ 0	$ 0	$ 0