Commitments and Contingencies - Commitments and Contingencies (Details)	3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended	6 Months Ended				0 Months Ended	1 Months Ended		12 Months Ended				6 Months Ended	3 Months Ended	6 Months Ended		6 Months Ended		1 Months Ended		6 Months Ended
	Jan. 31, 2013 USD ($)	Apr. 30, 2010	Apr. 30, 2013 USD ($) site	Apr. 30, 2012 USD ($)	Oct. 31, 2012	Apr. 30, 2013 Non-conformance Penalties [Member] USD ($)	Apr. 30, 2013 Non-conformance Penalties [Member] USD ($)	Apr. 30, 2012 Non-conformance Penalties [Member] USD ($)	Apr. 30, 2013 Pending Litigation [Member] FATMA Notice, Trial [Member] Penalties [Member] USD ($)	Apr. 30, 2013 Pending Litigation [Member] FATMA Notice, Trial [Member] Penalties [Member] BRL	Oct. 25, 2011 Pending Litigation [Member] Lis Franco vs. Syntex and MWM, Trial [Member] BRL	Apr. 30, 2013 Pending Litigation [Member] Lis Franco vs. Syntex and MWM, Trial [Member] USD ($)	Dec. 31, 2012 Pending Litigation [Member] Lis Franco vs. Syntex and MWM, Trial [Member] BRL	Dec. 31, 1999 Pending Litigation [Member] Lis Franco vs. Syntex and MWM, Trial [Member] Royalties [Member] BRL	May 30, 2010 Pending Litigation [Member] Lis Franco vs. Syntex and MWM, Trial [Member] Royalties [Member] BRL	Dec. 31, 2009 Pending Litigation [Member] Lis Franco vs. Syntex and MWM, Trial [Member] Royalties [Member] BRL	Apr. 30, 2013 Damages from Product Defects [Member] engine	Apr. 30, 2013 Damages from Product Defects [Member] Kruse Technology vs. Ford Motor Company [Member] patents	Apr. 30, 2013 California Air Resources Board (CARB) [Member] USD ($)	Apr. 30, 2013 G E Operating Agreement [Member] USD ($)	Oct. 31, 2012 G E Operating Agreement [Member] USD ($)	Apr. 30, 2013 Minimum [Member]	Apr. 30, 2013 Maximum [Member]	May 31, 2013 Subsequent Event [Member] Pending Litigation [Member] Lis Franco vs. Syntex and MWM, Trial [Member] BRL	Apr. 30, 2013 Subsequent Event [Member] Pending Litigation [Member] Lis Franco vs. Syntex and MWM, Trial [Member] USD ($)	Apr. 30, 2013 G E Operating Agreement [Member] USD ($)	Apr. 30, 2013 Manufacturing Operations [Member] Financed lease obligations [Member] USD ($)	Oct. 31, 2012 Manufacturing Operations [Member] Financed lease obligations [Member] USD ($)	Apr. 30, 2013 Manufacturing Operations [Member] G E Operating Agreement [Member] Financed lease obligations [Member] USD ($)	Oct. 31, 2012 Manufacturing Operations [Member] G E Operating Agreement [Member] Financed lease obligations [Member] USD ($)
Loss Contingencies [Line Items]
Length of Agreement		3 years
Length Of Potential Automatic Extension Years		1 year
Operating Agreement Excess Loss Percentage																				10.00%
Off Balance Sheet Finance Receivables																				$ 1,300,000,000	$ 1,200,000,000
Off Balance Sheet Finance Receivables Related Originations																				1,800,000,000	1,600,000,000
Payments to Acquire Equipment on Lease			295,000,000	28,000,000																						(185,000,000)
Long-term Debt																											209,000,000	0	209,000,000	167,000,000
Historical losses on finance receivables, measured as percentage of average balance of related finance receivable																						0.30%	2.10%
Available stand-by letters of credit and surety bonds			62,000,000
Line of Credit Facility, Remaining Borrowing Capacity			35,000,000
Purchase commitments			35,000,000
Long Term Purchase Commitment Cancellation Fees			224,000,000
Number of Contaminated Sites			3
Number of Contaminated Sites in Sao Paulo, Brazil			2
Accrual for environmental loss contingencies			24,000,000
Damages sought, value									1,000,000	2,000,000	10,850,000	11,000,000	22,000,000	42,000,000										25,000,000	13,000,000
Potential patent infringement, number of patents																		3
Estimate of possible loss														16,000,000	74,000,000	70,000,000
Proceeds from Legal Settlements	35,000,000
Notice of Violation, number																	7,600
Regulatory Penalty						$ 12,000,000	$ 22,000,000	$ 10,000,000											$ 2,000,000
Maximum Non-Conformance Penalty per unit			4,287		3,775
Number of States			9
10 CARB States			10 CARB States