Fair Value Measurements (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 31, 2013 Level 3	Oct. 31, 2013 Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Jul. 31, 2013 Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Oct. 31, 2013 Fair Value, Measurements, Recurring Level 1	Jul. 31, 2013 Fair Value, Measurements, Recurring Level 1	Oct. 31, 2013 Fair Value, Measurements, Recurring Level 2	Jul. 31, 2013 Fair Value, Measurements, Recurring Level 2	Oct. 31, 2013 Fair Value, Measurements, Recurring Level 3	Jul. 31, 2013 Fair Value, Measurements, Recurring Level 3	Oct. 31, 2013 Cash equivalents in cash and cash equivalents	Jul. 31, 2013 Cash equivalents in cash and cash equivalents	Oct. 31, 2013 Cash equivalents in cash and cash equivalents Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Jul. 31, 2013 Cash equivalents in cash and cash equivalents Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Oct. 31, 2013 Cash equivalents in cash and cash equivalents Fair Value, Measurements, Recurring Level 1	Jul. 31, 2013 Cash equivalents in cash and cash equivalents Fair Value, Measurements, Recurring Level 1	Oct. 31, 2013 Cash equivalents in cash and cash equivalents Fair Value, Measurements, Recurring Level 2	Jul. 31, 2013 Cash equivalents in cash and cash equivalents Fair Value, Measurements, Recurring Level 2	Oct. 31, 2013 Cash equivalents in cash and cash equivalents Fair Value, Measurements, Recurring Level 3	Jul. 31, 2013 Cash equivalents in cash and cash equivalents Fair Value, Measurements, Recurring Level 3	Oct. 31, 2013 Cash equivalents in funds held for customers Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Jul. 31, 2013 Cash equivalents in funds held for customers Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Oct. 31, 2013 Cash equivalents in funds held for customers Fair Value, Measurements, Recurring Level 1	Jul. 31, 2013 Cash equivalents in funds held for customers Fair Value, Measurements, Recurring Level 1	Oct. 31, 2013 Cash equivalents in funds held for customers Fair Value, Measurements, Recurring Level 2	Jul. 31, 2013 Cash equivalents in funds held for customers Fair Value, Measurements, Recurring Level 2	Oct. 31, 2013 Cash equivalents in funds held for customers Fair Value, Measurements, Recurring Level 3	Jul. 31, 2013 Cash equivalents in funds held for customers Fair Value, Measurements, Recurring Level 3	Oct. 31, 2013 Available For Sale Securities In Investments Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Jul. 31, 2013 Available For Sale Securities In Investments Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Oct. 31, 2013 Available For Sale Securities In Investments Fair Value, Measurements, Recurring Level 1	Jul. 31, 2013 Available For Sale Securities In Investments Fair Value, Measurements, Recurring Level 1	Oct. 31, 2013 Available For Sale Securities In Investments Fair Value, Measurements, Recurring Level 2	Jul. 31, 2013 Available For Sale Securities In Investments Fair Value, Measurements, Recurring Level 2	Oct. 31, 2013 Available For Sale Securities In Investments Fair Value, Measurements, Recurring Level 3	Jul. 31, 2013 Available For Sale Securities In Investments Fair Value, Measurements, Recurring Level 3	Oct. 31, 2013 Available For Sale Securities In Funds Held For Customers Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Jul. 31, 2013 Available For Sale Securities In Funds Held For Customers Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Oct. 31, 2013 Available For Sale Securities In Funds Held For Customers Fair Value, Measurements, Recurring Level 1	Jul. 31, 2013 Available For Sale Securities In Funds Held For Customers Fair Value, Measurements, Recurring Level 1	Oct. 31, 2013 Available For Sale Securities In Funds Held For Customers Fair Value, Measurements, Recurring Level 2	Jul. 31, 2013 Available For Sale Securities In Funds Held For Customers Fair Value, Measurements, Recurring Level 2	Oct. 31, 2013 Available For Sale Securities In Funds Held For Customers Fair Value, Measurements, Recurring Level 3	Jul. 31, 2013 Available For Sale Securities In Funds Held For Customers Fair Value, Measurements, Recurring Level 3	Oct. 31, 2013 Available For Sale Securities In long term investments Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Jul. 31, 2013 Available For Sale Securities In long term investments Fair Value, Measurements, Recurring Estimate of Fair Value Measurement [Member]	Oct. 31, 2013 Available For Sale Securities In long term investments Fair Value, Measurements, Recurring Level 1	Jul. 31, 2013 Available For Sale Securities In long term investments Fair Value, Measurements, Recurring Level 1	Oct. 31, 2013 Available For Sale Securities In long term investments Fair Value, Measurements, Recurring Level 2	Jul. 31, 2013 Available For Sale Securities In long term investments Fair Value, Measurements, Recurring Level 2	Oct. 31, 2013 Available For Sale Securities In long term investments Fair Value, Measurements, Recurring Level 3	Jul. 31, 2013 Available For Sale Securities In long term investments Fair Value, Measurements, Recurring Level 3
Cash equivalents:
Cash equivalents		$ 303	$ 917	$ 303	$ 917	$ 0	$ 0	$ 0	$ 0	$ 417	$ 1,009	$ 250	$ 857	$ 250	$ 857	$ 0	$ 0	$ 0	$ 0	$ 53	$ 60	$ 53	$ 60	$ 0	$ 0	$ 0	$ 0
Investments		$ 902	$ 893	$ 32	$ 33	$ 842	$ 827	$ 28	$ 33																			$ 699	$ 652	$ 32	$ 0	$ 667	$ 652	$ 0	$ 0	$ 175	$ 175	$ 0	$ 0	$ 175	$ 175	$ 0	$ 0	$ 28	$ 66	$ 0	$ 33	$ 0	$ 0	$ 28	$ 33
Number of auction rate securities redeemed	(5)
Number of auction rate securities still outstanding	28