Shareholders' Equity (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Common Shares, Authorized	755	755
Common Shares, No Par Value
Preferred Shares, Authorized	0.5	0.5
Preferred Shares, No Par Value
Treasury Stock, Value, Acquired, Cost Method	$ 450	$ 250	$ 250
Common Class A
Common Shares, Authorized	750	750
Common Shares, No Par Value
Common Stock, Voting Rights	one vote
Common Class B
Common Shares, Authorized	5	5
Common Shares, No Par Value
Common Stock, Voting Rights	one-fifth of one vote
Preferred Stock
Preferred Shares, Authorized	0.5	0.5
Preferred Shares, No Par Value
Treasury Stock
Treasury Stock, Value, Acquired, Cost Method	450	250	250
Treasury Stock, Shares, Acquired	10.3	7.5	7.4
Value of unsettled shares in period			20
Treasury Stock Acquired, Average Cost Per Share	$ 43.64	$ 33.22	$ 33.85
Three Year Aggregate | Treasury Stock
Treasury Stock, Value, Acquired, Cost Method	$ 950