Leverage Ratio on which Spread on Libor Borrowings and Commitment Fee for Unused Balance of Revolving Credit Agreement are Determined (Detail)	12 Months Ended
	Oct. 31, 2013
Scenario 1
Line of Credit Facility [Line Items]
Spread	0.50%
Commitment Fee	0.25%
Scenario 2
Line of Credit Facility [Line Items]
Spread	0.75%
Commitment Fee	0.30%
Scenario 3
Line of Credit Facility [Line Items]
Spread	1.25%
Commitment Fee	0.35%
Scenario 4
Line of Credit Facility [Line Items]
Spread	1.75%
Commitment Fee	0.40%
Scenario 5
Line of Credit Facility [Line Items]
Spread	2.25%
Commitment Fee	0.50%
Minimum | Scenario 2
Line of Credit Facility [Line Items]
Leverage Ratio	25.00%
Minimum | Scenario 3
Line of Credit Facility [Line Items]
Leverage Ratio	35.00%
Minimum | Scenario 4
Line of Credit Facility [Line Items]
Leverage Ratio	45.00%
Minimum | Scenario 5
Line of Credit Facility [Line Items]
Leverage Ratio	55.00%
Maximum | Scenario 1
Line of Credit Facility [Line Items]
Leverage Ratio	25.00%
Maximum | Scenario 2
Line of Credit Facility [Line Items]
Leverage Ratio	35.00%
Maximum | Scenario 3
Line of Credit Facility [Line Items]
Leverage Ratio	45.00%
Maximum | Scenario 4
Line of Credit Facility [Line Items]
Leverage Ratio	55.00%