Long-Term Obligations and Commitments (Details)		1 Months Ended	3 Months Ended	9 Months Ended
	Feb. 01, 2016 USD ($)	Jan. 31, 2016 USD ($)	Apr. 30, 2016 USD ($)	Apr. 30, 2016 USD ($)	Apr. 30, 2015 USD ($)	Jul. 31, 2015 USD ($)
Debt Instrument [Line Items]
Long-term debt			$ 500,000,000	$ 500,000,000		$ 500,000,000
Long Term Obligations (Textuals)
Cash paid for interest on the Notes				29,000,000	$ 29,000,000
Other long-term obligations
Total deferred rent			57,000,000	57,000,000		49,000,000
Total license fee payable			36,000,000	36,000,000		34,000,000
Long-term income tax liabilities			51,000,000	51,000,000		45,000,000
Long-term deferred income tax liabilities			5,000,000	5,000,000		50,000,000
Other			22,000,000	22,000,000		13,000,000
Total long-term obligations			171,000,000	171,000,000		191,000,000
Less current portion (included in other current liabilities)			(18,000,000)	(18,000,000)		(19,000,000)
Long-term obligations due after one year			153,000,000	153,000,000		$ 172,000,000
Building and Building Improvements
Other long-term obligations
Purchase of leased facilities		$ 262,000,000
Term Loan
Long Term Obligations (Textuals)
Cash paid for interest on the Notes			1,000,000
February 1, 2016 Credit Agreement
Long Term Obligations (Textuals)
Debt instrument, term	5 years
Master credit agreement	$ 1,500,000,000.0
February 1, 2016 Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Debt to EBITDA ratio (not greater than)	3.25
EBITDA to interest payable ratio (not less than)	3.00
Periodic principal payment percentage	2.50%
February 1, 2016 Credit Agreement | Line of Credit | Term Loan
Debt Instrument [Line Items]
Long-term debt			$ 500,000,000	$ 500,000,000
Long Term Obligations (Textuals)
Term loan	$ 500,000,000
Term loan, increase limit	500,000,000
February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility
Long Term Obligations (Textuals)
Unsecured revolving credit facility	$ 1,000,000,000
Base Rate | Minimum | February 1, 2016 Credit Agreement | Line of Credit | Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate	0.125%
Base Rate | Minimum | February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate	0.00%
Base Rate | Maximum | February 1, 2016 Credit Agreement | Line of Credit | Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate	0.875%
Base Rate | Maximum | February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
LIBOR | Minimum | February 1, 2016 Credit Agreement | Line of Credit | Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate	1.125%
LIBOR | Minimum | February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate	0.90%
LIBOR | Maximum | February 1, 2016 Credit Agreement | Line of Credit | Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate	1.875%
LIBOR | Maximum | February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%