Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share Basic And Diluted [Abstract]
Net income (loss) available for common shareholders (A)	$ 8,420	$ (6,302)	$ 17,244	$ 274
Weighted average outstanding shares of common stock (B)	7,692	7,710	7,683	7,709
Dilutive effect of stock-based awards	76	0	84	90
Common stock and common stock equivalents (C)	7,768	7,710	7,767	7,799
Earnings (Loss) Per Share
Basic (A/B)	$ 1.09	$ (0.82)	$ 2.24	$ 0.04
Diluted (A/C)	$ 1.08	$ (0.82)	$ 2.22	$ 0.04