Marketable Securities And Cash Equivalents (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2011 securities	Dec. 31, 2011 Equity Securities [Member]	Jun. 30, 2011 Equity Securities [Member]
Other than temporary impairment losses, investments, available-for-sale securities	$ 13		$ 13
Unrealized losses that arose within the last 12 months	3	3
Market value of the investments that have been in an unrealized loss position for less than 12 months			31
Unrealized losses on available-for-sale securities			$ 3	$ 4
Number of available-for-sale equity securities with unrealized losses (in securities)		1