Discontinued Operations - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	0 Months Ended		3 Months Ended			12 Months Ended
	Oct. 31, 2013	Oct. 21, 2013	Oct. 31, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of bus business		$ 100,000			$ 97,677	$ 105,043
Proceeds from sale of bus business, net of cash divested						97,677
Sale of bus business, cash divested						2,323
Discontinued operation, total amounts due from ASV	8,329
Discontinued operation, amounts collected from ASV						5,043
Pre-tax gain (loss) on sale of business				(746)	7,825	7,079
Impact of indemnification to tax expenses					1,883
Income tax benefit (expense)			$ 159		$ 322