Commitments and Contingencies - Narrative (Details) R$ in Millions		1 Months Ended		3 Months Ended									6 Months Ended		9 Months Ended
	Jul. 16, 2015 USD ($)	Oct. 31, 2016 members	Mar. 31, 2014 BRL (R$)	Apr. 30, 2018 USD ($)	Jan. 31, 2018 USD ($)	Oct. 31, 2017 USD ($)	Jul. 31, 2017 USD ($)	Apr. 30, 2017 USD ($)	Oct. 31, 2016 USD ($) employees lawsuits plaintiff	Jul. 31, 2014 lawsuits	Jan. 31, 2014 BRL (R$)	Jul. 31, 2010 BRL (R$)	Apr. 30, 2018 USD ($) dealer	Apr. 30, 2017 USD ($)	Jul. 31, 2018 USD ($)	Jul. 31, 2015 engine
Loss Contingencies [Line Items]
Long-term Debt				$ 0									$ 0
Available stand-by letters of credit and surety bonds				119,000,000									119,000,000
Purchase commitments				82,000,000									82,000,000
Long Term Purchase Commitment Cancellation Fees													22,000,000
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral				228,000,000									228,000,000
Accrual for environmental loss contingencies				19,000,000									19,000,000
Damages sought, value				50,000,000		$ 31,000,000
Loss Contingency, Number of Potential Additional Plaintiffs | employees									1,000
Loss Contingency, Number of Plaintiffs		2							25
Loss Contingency, New Claims Filed, Number | lawsuits									2	17
Notice of Violation, number | engine																7,749
Civil penalties sought, per violation	$ 37,500
Loss Contingency, Overcharge Penalty						88,000,000
Loss Contingency, Damages Sought, Value, Punitive Damages						20,000,000
Legal Fees					$ 1,360,000
Selling, general and administrative expenses				$ 220,000,000			$ 31,000,000	$ 221,000,000					442,000,000	$ 421,000,000
Loss Contingency, Damages Sought						264,000,000
Gain (Loss) Related to Litigation Settlement															$ 85,000,000
Gain from Settlement, Net															$ 70,000,000
Sao Paulo Groundwater Notice [Member] | Sanctions [Member]
Loss Contingencies [Line Items]
Damages sought, value			R$ 3										1,000,000
International Chamber of Commerce [Member] | Penalties and Interest [Member]
Loss Contingencies [Line Items]
Damages sought, value													18,000,000
Navitrucks [Member] | Alleged Unfulfilled Promises and Injury to Reputation [Member]
Loss Contingencies [Line Items]
Damages sought, value													$ 37,000,000
G E Operating Agreement [Member]
Loss Contingencies [Line Items]
Operating Agreement Excess Loss Percentage													10.00%
Loss Sharing Agreement, Percentage				9.50%									9.50%
Off Balance Sheet Finance Receivables				$ 1,400,000,000									$ 1,400,000,000
Off Balance Sheet Finance Receivables Related Originations1				2,500,000,000		2,400,000,000							2,500,000,000
Minimum [Member] | Damages from Product Defects [Member] | EPA [Member]
Loss Contingencies [Line Items]
Civil penalties sought, per violation	2,000,000
Maximum [Member] | Damages from Product Defects [Member] | EPA [Member]
Loss Contingencies [Line Items]
Civil penalties sought, per violation	$ 291,000,000
G E Operating Agreement [Member]
Loss Contingencies [Line Items]
Equipment leased to others				110,000,000		116,000,000							110,000,000
Manufacturing Operations [Member] | Financed lease obligations [Member]
Loss Contingencies [Line Items]
Long-term Debt				126,000,000		130,000,000							126,000,000
Manufacturing Operations [Member] | G E Operating Agreement [Member] | Financed lease obligations [Member]
Loss Contingencies [Line Items]
Long-term Debt				$ 126,000,000		$ 129,000,000							126,000,000
Pending Litigation [Member] | FATMA Notice, Trial [Member] | Penalties [Member]
Loss Contingencies [Line Items]
Damages sought, value												R$ 2	1,000,000
Profit Sharing Litigation [Member] | Pending Litigation [Member] | Disputes [Member]
Loss Contingencies [Line Items]
Damages sought, value									$ 50,000,000
Retiree Health Care [Member]
Loss Contingencies [Line Items]
Damages sought, value													$ 26,000,000
Brazil, Brazil Real | International Chamber of Commerce [Member] | Penalties and Interest [Member]
Loss Contingencies [Line Items]
Damages sought, value | R$											R$ 64
Brazil, Brazil Real | Navitrucks [Member] | Alleged Unfulfilled Promises and Injury to Reputation [Member]
Loss Contingencies [Line Items]
Damages sought, value | R$											R$ 128
International Indústria de Motores da América do Sul Ltda [Member] | Other Cases Vs. International Indústria de Motores da América do Sul Ltda [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Truck Fleet Owners | dealer													2