Derivative Instruments (Derivatives Recorded at Fair Value) (Details) (USD $) In Millions	Apr. 30, 2011	Jul. 31, 2010
Derivative assets, designated	$ 175	$ 154
Derivative liabilities, designated	14	7
Derivative assets, not designated	10	9
Derivative liabilities, not designated	8	12
Total derivative assets, fair value	185	163
Total derivative liabilities, fair value	22	19
Foreign Currency Derivatives [Member] | Other Current Assets [Member]
Derivative assets, designated	100	82
Derivative assets, not designated	8	6
Foreign Currency Derivatives [Member] | Other Current Liabilities [Member]
Derivative liabilities, designated	14	7
Derivative liabilities, not designated	8	12
Other Assets [Member] | Interest Rate Derivatives [Member]
Derivative assets, designated	75	72
Other Long-Term Liabilities [Member] | Interest Rate Derivatives [Member]
Derivative liabilities, designated
Other Assets [Member] | Equity Derivatives [Member]
Derivative assets, not designated	2	2
Other Current Liabilities [Member] | Equity Derivatives [Member]
Derivative liabilities, not designated
Total Return Swaps-Deferred Compensation [Member] | Other Current Assets [Member]
Derivative assets, not designated		1
Total Return Swaps-Deferred Compensation [Member] | Other Long-Term Liabilities [Member]
Derivative liabilities, not designated