Summary of Changes in Accumulated Other Comprehensive Income by Component (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains, tax effects	$ 0	$ 1
Net change related to other comprehensive income (loss), tax	(1)	(2)
Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains, tax effects	50	182
Net change related to other comprehensive income (loss), tax	(144)	44
Translation Adjustments and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net change related to other comprehensive income (loss), tax	$ (1)	$ 7