Marketable Securities And Cash Equivalents (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Sep. 30, 2011 securities	Jun. 30, 2011
Unrealized losses that arose within the last 12 months	$ 35
Market value of the investments that have been in an unrealized loss position for less than 12 months	164
Equity Securities [Member]
Market value of the investments that have been in an unrealized loss position for less than 12 months	114
Unrealized losses on available-for-sale securities	34	4
Available For Sale Securities Unrealized Losses On Specified Number of Securities	20
Number of available-for-sale equity securities with unrealized losses (in securities)	1
Corporate Debt Securities [Member]
Market value of the investments that have been in an unrealized loss position for less than 12 months	50
Unrealized losses on available-for-sale securities	$ 1