Restructuring (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		21 Months Ended	3 Months Ended							9 Months Ended	21 Months Ended	12 Months Ended	15 Months Ended	3 Months Ended	21 Months Ended	12 Months Ended	9 Months Ended		21 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended				15 Months Ended	9 Months Ended		12 Months Ended	9 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2012	Jul. 31, 2011	Oct. 31, 2012 Minimum [Member]	Oct. 31, 2012 Maximum [Member]	Jul. 31, 2012 Fort Wayne, Springfield, Chatham and Custom Products [Member]	Jul. 31, 2011 Fort Wayne, Springfield, Chatham and Custom Products [Member]	Jul. 31, 2012 Fort Wayne And Springfield [Member] Truck [Member]	Jul. 31, 2011 Fort Wayne And Springfield [Member] Truck [Member]	Jul. 31, 2012 Fort Wayne And Springfield [Member] Truck [Member]	Jul. 31, 2011 Fort Wayne And Springfield [Member] Truck [Member]	Jul. 31, 2012 Fort Wayne And Springfield [Member] Truck [Member]	Jul. 31, 2012 Chatham [Member] Truck [Member] Minimum [Member]	Jul. 31, 2012 Chatham [Member] Truck [Member] Maximum [Member]	Jul. 31, 2012 Custom Products [Member] Truck [Member]	Jul. 31, 2011 Custom Products [Member] Truck [Member]	Jul. 31, 2012 Custom Products [Member] Truck [Member] Minimum [Member]	Jul. 31, 2012 Custom Products [Member] Truck [Member] Maximum [Member]	Jul. 31, 2012 Custom Products [Member] Parts [Member]	Jul. 31, 2012 Employee Termination Charges [Member] Fort Wayne, Springfield, Chatham and Custom Products [Member]	Jul. 31, 2012 Employee Termination Charges [Member] Fort Wayne And Springfield [Member] Truck [Member]	Apr. 30, 2012 Employee Termination Charges [Member] Chatham [Member] Truck [Member]	Jul. 31, 2012 Employee Termination Charges [Member] Custom Products [Member] Truck [Member]	Jan. 31, 2012 Employee Termination Charges [Member] Location Springfield Assembly Plant [Member] Truck [Member]	Jul. 31, 2012 Pension and Other Postretirement Contractual Termination Benefits [Member] Fort Wayne And Springfield [Member] Truck [Member]	Apr. 30, 2012 Pension and Other Postretirement Contractual Termination Benefits [Member] Chatham [Member] Truck [Member]	Jul. 31, 2012 Employee Relocation Costs [Member] Fort Wayne, Springfield, Chatham and Custom Products [Member]	Jul. 31, 2011 Employee Relocation Costs [Member] Fort Wayne, Springfield, Chatham and Custom Products [Member]	Jul. 31, 2012 Employee Relocation Costs [Member] Fort Wayne And Springfield [Member] Truck [Member]	Jul. 31, 2011 Lease Vacancy [Member] [Domain] Warrenville [Member] Truck [Member]	Jul. 31, 2012 Lease Vacancy [Member] [Domain] Fort Wayne, Springfield, Chatham and Custom Products [Member]	Jul. 31, 2011 Lease Vacancy fair value [Member] [Domain] Warrenville [Member] Truck [Member]	Jul. 31, 2011 Accrued Rent Expense, Reversal [Domain] Warrenville [Member] Truck [Member]	Jul. 31, 2011 Facility Closing [Member] Chatham [Member] Truck [Member]	Jul. 31, 2011 Facility Closing [Member] Custom Products [Member] Truck [Member]	Jul. 31, 2012 Facility Closing [Member] Custom Products [Member] Truck [Member]	Jul. 31, 2012 Other Contractual Costs [Member] Fort Wayne, Springfield, Chatham and Custom Products [Member]	Jul. 31, 2011 Other Contractual Costs [Member] Fort Wayne, Springfield, Chatham and Custom Products [Member]	Apr. 30, 2012 Other Contractual Costs [Member] Chatham [Member] Truck [Member]	Jul. 31, 2011 Ford [Member] Employee Termination Charges [Member] Location IEP And ICC [Member]	Jul. 31, 2012 Tax Exempt Bond [Member] Manufacturing Operations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve							$ 41	$ 33													$ 21							$ 0	$ 0			$ 18						$ 2	$ 7		$ 26
Debt Instrument, Interest Rate, Stated Percentage																																										6.50%
Expected restructuring and related charges														30	70			30	40
Impairment of Intangible Assets (Excluding Goodwill)			38	73												28	51			10
Restructuring Charges Length Of Payment Period	2
Restructuring Reserve [Roll Forward]
Restructuring liability, balance at beginning of period							39	5													31							0	0			0						8	0		5
Restructuring charges	4	56	24	80			29	36	2	4	5	23	34								2	13	7	6	4	7	33	6	4	14	16	19	19	3	48	5	10	2	7	8	25
Payments							(23)	(8)													(8)							(6)	(4)			(2)						(7)	0		(4)
Adjustments							(4)	0													(4)							0	0			1						(1)	0		0
Restructuring liability, balance at end of period							41	33													21							0	0			18						2	7		26
Severance Costs					40
Voluntary Seperation Plan High End of Range Estimate						$ 60