Derivative Instruments and Hedging Activities (Changes in AOCI Related to Derivative Gains (Losses)) (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2012 Deferred Gain (Loss) On Hedging Activities [Member]	Sep. 30, 2011 Deferred Gain (Loss) On Hedging Activities [Member]
Balance of Accumulated Other Comprehensive Income (Loss) at beginning of period	$ (734)	$ (907)	$ 50	$ 29
Unrealized gains			142	6
Gains reclassified to earnings			(88)	(3)
Tax effect			(18)	(2)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	$ (734)	$ (907)	$ 86	$ 30