Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Unrealized holding gains (losses) on securities, income tax expense (benefit)	$ 1		$ 3	$ (8)
Benefit plan adjustments, income tax (benefit) expense	$ 2	$ 1	$ 4	7
Share of other comprehensive (loss) income from equity affiliates, income tax expense		$ 3		$ 2