Restructuring and Impairments - Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		6 Months Ended	3 Months Ended									9 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013 Truck [Domain]	Oct. 31, 2012 Truck [Domain] Garland Assembly Plant [Member] Employee Severance [Member]	Apr. 30, 2013 Truck [Domain] Garland Assembly Plant [Member] Garland plant closure [Member]	Apr. 30, 2012 Truck [Domain] Warrenville [Member] Accrued Rent Expense, Reversal [Domain]	Apr. 30, 2012 Truck [Domain] Warrenville [Member] Lease Vacancy [Member]	Apr. 30, 2012 Truck [Domain] Warrenville [Member] Lease Vacancy Fair Value [Member]	Apr. 30, 2012 Truck [Domain] Workhorse Custom Chassis [Member]	Jul. 31, 2013 Engine [Member]	Apr. 30, 2012 Parts [Member] Workhorse Custom Chassis [Member]	Oct. 31, 2012 Voluntary Separation Program [Member]	Oct. 31, 2012 Voluntary Separation Program [Member] Pension And Other Postretirement Contractual Termination Benefits [Member]	Oct. 31, 2012 Voluntary Separation Program [Member] Employee Severance [Member]	Jul. 31, 2013 Minimum [Member] Truck [Domain] Chatham [Member]	Jul. 31, 2013 Maximum [Member] Truck [Domain] Garland Assembly Plant [Member] Garland plant closure [Member]	Jul. 31, 2013 Maximum [Member] Truck [Domain] Chatham [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 6	$ 4	$ 14	$ 23		$ 4	$ 22	$ 3	$ 16	$ 19				$ 73	$ 7	$ 66
Asset impairment charges	17	0	17	10
Asset Impairment Charges	24				13							4
Restructuring and Related Cost, Expected Cost																	20	10	70
Impairment of Intangible Assets (Excluding Goodwill)			$ 25	$ 38							$ 28		$ 10