Post Retirement Benefit Plans - Schedule of Other Comprehensive Income Included in Financial Statement (Detail) - USD ($) $ in Millions	Oct. 31, 2015	Oct. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Unrecognized net actuarial gain	$ 1.6	$ 0.8
Unrecognized prior service credit	5.8	7.4
Accumulated other comprehensive income	$ 7.4	$ 8.2

Amount after tax of cost (credit) due to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation, which has not yet been recognized as a component of net periodic benefit cost.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Prior Service Cost
-URI http://asc.fasb.org/extlink&oid=49177896

Name:	us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant