Long-Term Debt (Details)	Oct. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 25, 2015 USD ($)	Apr. 30, 2015 USD ($)	Oct. 31, 2014 USD ($)
Debt Instrument [Line Items]
Long-term debt	$ 1,502,746,000			$ 506,088,000	$ 506,360,000
Less: Current portion	(808,000)			(790,000)	(772,000)
Long-term debt excluding current portion	1,501,938,000			505,298,000	505,588,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 2,000,000,000.0
Available increase in borrowing capacity		$ 500,000,000.0
Maximum quarterly debt-to-EBITDA ratio		3.50
Maximum annual debt-to-EBITDA ratio		4.50
Minimum interest coverage ratio		2.50
Swingline Loans [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 200,000,000.0
Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 100,000,000.0
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Long-term debt	7,835,000			8,194,000	8,607,000
Senior Notes due 2020 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt	647,918,000
Debt issued			$ 650,000,000.0
Interest rate (as a percent)			4.125%
Senior Notes due 2022 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt	498,034,000			$ 497,894,000	$ 497,753,000
Senior Notes due 2025 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 348,959,000
Debt issued			$ 350,000,000.0
Interest rate (as a percent)			5.25%