Equity - Summary of Changes in Equity (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Equity [Abstract]
Balance, beginning of period			$ 10,789	$ 11,564
Net (loss) income	$ (1,128)	$ (5)	(1,143)	(309)
Other comprehensive income (loss)			135	(18)
Dividends			(118)	(118)
Other			32	20
Balance, end of period	9,695	11,139	9,695	11,139
Balance, beginning of period			284	218
Net (loss) income	18	5	54	90
Other comprehensive income (loss)			1	7
Dividends			(40)	(33)
Other			(3)	(4)
Balance, end of period	296	278	296	278
Balance, beginning of period			11,073	11,782
Net (loss) income	(1,110)	0	(1,089)	(219)
Other comprehensive income (loss)	1	257	136	(11)
Dividends			(158)	(151)
Other			29	16
Balance, end of period	$ 9,991	$ 11,417	$ 9,991	$ 11,417