Fair Value Measurements (Details 2) (Significant Unobservable Inputs (Level 3), USD $) In Millions, unless otherwise specified	12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Minimum threshold of relative value of unobservable inputs to the total fair value for Level 3 (as a percent)	10.00%
Fair Value, Measurements, Recurring
Reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance at beginning of period	$ 440	$ 466
Total gains (losses), realized or unrealized, included in earnings before income taxes	250	37
Purchases, issuances and settlements	252	(55)
Transfers into Level 3	323
Transfers out of Level 3	(480)
Transfers in and/or out of Level 3		(8)
Balance at end of period	785	440
Unrealized gains (losses) on derivative assets	109	6
Fair Value, Measurements, Recurring | Inventories Carried at Market, Net
Reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance at beginning of period	427	468
Total gains (losses), realized or unrealized, included in earnings before income taxes	171	7
Purchases, issuances and settlements	254	(29)
Transfers into Level 3	300
Transfers out of Level 3	(435)
Transfers in and/or out of Level 3		(19)
Balance at end of period	717	427
Fair Value, Measurements, Recurring | Derivative Contracts, Net
Reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance at beginning of period	13	(2)
Total gains (losses), realized or unrealized, included in earnings before income taxes	79	30
Purchases, issuances and settlements	(2)	(26)
Transfers into Level 3	23
Transfers out of Level 3	(45)
Transfers in and/or out of Level 3		11
Balance at end of period	$ 68	$ 13