Current Liabilities - Additional Information (Details)		12 Months Ended
	Feb. 01, 2016 USD ($) extension	Jul. 31, 2017 USD ($)	Jul. 31, 2016 USD ($)	Jul. 31, 2015 USD ($)
Debt Instrument [Line Items]
Cash paid for interest		$ 42,000,000	$ 37,000,000	$ 32,000,000
Short-term debt		50,000,000	512,000,000
Repayments under revolving credit facility		150,000,000	995,000,000	0
Borrowings under revolving credit facility		150,000,000	995,000,000	0
Term Loan
Debt Instrument [Line Items]
Cash paid for interest		11,000,000	4,000,000
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Cash paid for interest			2,000,000
5.75 percent fixed-rate notes due 2017
Debt Instrument [Line Items]
Senior notes, amount			$ 500,000,000
Senior notes, rate			5.75%
Cash paid for interest		29,000,000	$ 29,000,000	$ 29,000,000
February 1, 2016 Credit Agreement
Debt Instrument [Line Items]
Credit agreement, term	5 years
Credit agreement amount	$ 1,500,000,000
February 1, 2016 Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Repayments under revolving credit facility		150,000,000
Borrowings under revolving credit facility		150,000,000
February 1, 2016 Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Debt instrument, covenant, debt To EBITDA ratio, maximum	3.25
Debt instrument, covenant, EBITDA to annual interest expense ratio, minimum	3.00
February 1, 2016 Credit Agreement | Line of Credit | Term Loan
Debt Instrument [Line Items]
Term loan amount outstanding	$ 500,000,000	488,000,000
Short-term debt		50,000,000
February 1, 2016 Credit Agreement | Line of Credit | Term Loan | Minimum | Base Rate
Debt Instrument [Line Items]
Libor plus variable interest rate on advances under credit facilities	0.125%
February 1, 2016 Credit Agreement | Line of Credit | Term Loan | Minimum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Libor plus variable interest rate on advances under credit facilities	1.125%
February 1, 2016 Credit Agreement | Line of Credit | Term Loan | Maximum | Base Rate
Debt Instrument [Line Items]
Libor plus variable interest rate on advances under credit facilities	0.875%
February 1, 2016 Credit Agreement | Line of Credit | Term Loan | Maximum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Libor plus variable interest rate on advances under credit facilities	1.875%
February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Cash paid for interest		1,000,000
Revolving credit facility, amount	$ 1,000,000,000
Revolving credit facility, increase limit	$ 250,000,000
Debt instrument, maturity date extension | extension	2
Fair value of amount outstanding		$ 0
February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility | Minimum | Base Rate
Debt Instrument [Line Items]
Libor plus variable interest rate on advances under credit facilities	0.00%
February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility | Minimum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Libor plus variable interest rate on advances under credit facilities	0.90%
February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility | Maximum | Base Rate
Debt Instrument [Line Items]
Libor plus variable interest rate on advances under credit facilities	0.50%
February 1, 2016 Credit Agreement | Line of Credit | Revolving Credit Facility | Maximum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Libor plus variable interest rate on advances under credit facilities	1.50%