Shareholders' Equity (Narrative) (Details) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended			36 Months Ended
	Mar. 21, 2018 USD ($) $ / shares shares	Jun. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2018 USD ($) $ / shares shares	Jun. 30, 2017 USD ($) $ / shares shares	Jun. 30, 2019 USD ($) shares
Class of Stock [Line Items]
Common shares, authorized | shares		755,000,000	755,000,000		755,000,000
Preferred shares, authorized | shares		500,000	500,000		500,000
Treasury shares acquired | $		$ 600	$ 550	$ 600
Payments for Repurchase of Common Stock | $		600	550	600
Retained earnings decrease | $		(5,434)	(4,645)		$ (5,434)
Treasury Shares
Class of Stock [Line Items]
Treasury shares acquired | $		$ 600	$ 550	$ 600	$ 1,800
Treasury Stock, Shares, Acquired | shares		11,500,000	8,400,000	8,100,000
Treasury shares acquired, average price per share (in usd per share) | $ / shares		$ 52.32	$ 65.30	$ 74.08
Retirement of Treasury Shares (in shares) | shares				37,000,000
Common Class A
Class of Stock [Line Items]
Common shares, authorized | shares		750,000,000	750,000,000		750,000,000
Common Stock, Voting Rights, Votes		1
Common Class B
Class of Stock [Line Items]
Common shares, authorized | shares		5,000,000	5,000,000		5,000,000
Common Stock, Voting Rights, Votes		0.2
Retirement of Treasury Shares [Member]
Class of Stock [Line Items]
Retirement of Treasury Shares (in shares) | shares				37,000,000
Decrease in Common Shares in Treasury | $				$ 2,500
Decrease in Common Shares, Value | $				302
Retained earnings decrease | $				$ 2,200
Accelerated share repurchase plan | Treasury Shares
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired | shares	4,300,000
Payments for Repurchase of Common Stock | $	$ 300
Treasury shares acquired, average price per share (in usd per share) | $ / shares	$ 69.26