Summary of Changes in Accumulated Other Comprehensive Income (Loss) by Component (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses), tax	$ 11	$ 4	$ 24
Net change related to other comprehensive income (loss), tax	5	(5)	(12)
Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses), tax	(427)	267	120
Net change related to other comprehensive income (loss), tax	(1,165)	(613)	(121)
Translation adjustments and other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net change related to other comprehensive income (loss), tax	$ 0	$ 9	$ (33)