Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net change in the fair value of cash flow hedges income tax expense (benefit)	$ 0		$ 1
Unrealized holding (losses) gains on securities, income tax (benefit) expense		$ 8		$ 2
Benefit plan adjustments, income tax expense (benefit)	2	0	3	(2)
Share of other comprehensive (loss) income from equity affiliates, income tax expense (benefit)	$ 0	$ 0	$ 0	$ 0