Long-Term Debt - Credit Agreement Additional Information (Detail)	Nov. 03, 2016 USD ($)	Apr. 30, 2018 USD ($)	Oct. 31, 2017 USD ($)	Dec. 19, 2012 USD ($)	Feb. 09, 2007 USD ($)
Debt Instrument [Line Items]
Less deferred financing costs		$ 5,500,000	$ 6,400,000
Long-term debt		1,041,000,000	959,200,000
Current portion of long-term debt		15,000,000	15,000,000
Long-term debt, excluding current maturities		1,020,500,000	937,800,000
2017 Credit Agreement
Debt Instrument [Line Items]
Debt issued	$ 300,000,000.0
Optional additional borrowing capacity	$ 550,000,000
Leverage ratio, adjusted EBITDA	4.00
Leverage ratio, adjusted EBITDA during collateral release period	3.75
Interest coverage ratio, adjusted EBITDA	3.00
Long-term debt		$ 396,200,000
Weighted average interest rate		2.82%
Actual interest rate		3.11%
Senior Notes One
Debt Instrument [Line Items]
Debt issued					$ 300,000,000
Interest of senior notes					6.75%
Revolving Credit Facility | 2017 Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 800,000,000
Reduction in outstanding letter of credit		$ 14,400,000
Less deferred financing costs		4,900,000
Long-term debt		114,900,000	$ 35,000,000
Current portion of long-term debt		15,000,000
Long-term debt, excluding current maturities		381,200,000
Line of Credit | Prior Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 1,000,000,000
Current borrowing available		$ 670,700,000