Annual report pursuant to Section 13 and 15(d)

INVESTMENTS IN EQUITY INVESTEES (Details)

v2.4.1.9
INVESTMENTS IN EQUITY INVESTEES (Details) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Sep. 28, 2014
l
Equity, royalty and interest income from investees        
Investments and advances related to equity method investees $ 981us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures $ 931us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures $ 897us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures  
Cummins share of net income 330us-gaap_IncomeLossFromEquityMethodInvestments 325us-gaap_IncomeLossFromEquityMethodInvestments 347us-gaap_IncomeLossFromEquityMethodInvestments  
Royalty and interest income 40cmi_RoyaltyAndInterestIncomeFromInvesteesOperating 36cmi_RoyaltyAndInterestIncomeFromInvesteesOperating 37cmi_RoyaltyAndInterestIncomeFromInvesteesOperating  
Equity, royalty and interest income from investees 370cmi_EquityRoyaltyAndInterestIncomeFromInvestees 361cmi_EquityRoyaltyAndInterestIncomeFromInvestees 384cmi_EquityRoyaltyAndInterestIncomeFromInvestees  
Minimum        
Equity, royalty and interest income from investees        
Ownership percentage 20.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		     
Maximum        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		     
Distribution - North American distributors        
Equity, royalty and interest income from investees        
Investments and advances related to equity method investees 41us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		[1] 114us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		   
Cummins share of net income 107us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		129us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		147us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		 
Number of partially-owned distributors 3cmi_DistributorsNumberOfPartiallyOwnedDistributors
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		     
Minimum ownership percentage in partially-owned distributors that are consolidated 50.00%cmi_ConsolidatedMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		     
Number of partially-owned distributors, consolidated 2cmi_DistributorsConsolidatedNumberOfPartiallyOwnedDistributors
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		     
Distribution - North American distributors | Minimum        
Equity, royalty and interest income from investees        
Ownership percentage 49.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		[1]      
Distribution - North American distributors | Maximum        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_NorthAmericanDistributorsMember 		[1]      
Distribution - Komatsu Cummins Chile, Ltda.        
Equity, royalty and interest income from investees        
Cummins share of net income 29us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_KomatsuCumminsChileLtdaMember 		25us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_KomatsuCumminsChileLtdaMember 		26us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_KomatsuCumminsChileLtdaMember 		 
Distribution - All other distributors        
Equity, royalty and interest income from investees        
Cummins share of net income 4us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_AllOtherDistributorsMember 		1us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_AllOtherDistributorsMember 		4us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_AllOtherDistributorsMember 		 
Distribution - International Distributors        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_InternationalDistributorsMember 		     
Number of partially-owned distributors 5cmi_DistributorsNumberOfPartiallyOwnedDistributors
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_InternationalDistributorsMember 		     
Manufacturing Entities | Maximum        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_ManufacturingEntitiesMember 		     
Manufacturing - Dongfeng Cummins Engine Company, Ltd.        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		     
Investments and advances related to equity method investees 136us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		135us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		   
Cummins share of net income 67us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		63us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		52us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		 
Manufacturing - Dongfeng Cummins Engine Company, Ltd. | Minimum        
Equity, royalty and interest income from investees        
Capacity of mechanical engines (in liters) 4cmi_CapacityOfMechanicalEngine
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		     
Power of mechanical engines (in horsepower) 125cmi_PowerOfMechanicalEngines
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		     
Manufacturing - Dongfeng Cummins Engine Company, Ltd. | Maximum        
Equity, royalty and interest income from investees        
Capacity of mechanical engines (in liters) 13cmi_CapacityOfMechanicalEngine
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		     
Power of mechanical engines (in horsepower) 545cmi_PowerOfMechanicalEngines
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_DongfengCumminsEngineCompanyLtdMember 		     
Manufacturing - Chongqing Cummins Engine Company, Ltd.        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_ChongqingCumminsEngineCompanyLtdMember 		     
Investments and advances related to equity method investees 92us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_ChongqingCumminsEngineCompanyLtdMember 		67us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_ChongqingCumminsEngineCompanyLtdMember 		   
Cummins share of net income 51us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_ChongqingCumminsEngineCompanyLtdMember 		58us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_ChongqingCumminsEngineCompanyLtdMember 		61us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_ChongqingCumminsEngineCompanyLtdMember 		 
Manufacturing - Beijing Foton Cummins Engine Co., Ltd.        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyMember 		[2]      
Investments and advances related to equity method investees 117us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyMember 		[2] 103us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyMember 		[2]    
Manufacturing - Beijing Foton Cummins Engine Company (Light-Duty) [Member]        
Equity, royalty and interest income from investees        
Cummins share of net income 28us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyLightDutyMember 		17us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyLightDutyMember 		5us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyLightDutyMember 		 
Manufacturing - Beijing Foton Cummins Engine Company (Light-Duty) [Member] | Minimum        
Equity, royalty and interest income from investees        
Capacity of mechanical engines (in liters)       2.8cmi_CapacityOfMechanicalEngine
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyLightDutyMember
Manufacturing - Beijing Foton Cummins Engine Company (Light-Duty) [Member] | Maximum        
Equity, royalty and interest income from investees        
Capacity of mechanical engines (in liters)       3.8cmi_CapacityOfMechanicalEngine
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyLightDutyMember
Manuafacturing - Beijing Foton Cummins Engine Company (Heavy-Duty) [Member]        
Equity, royalty and interest income from investees        
Cummins share of net income (30)us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyHeavyDutyMember 		(21)us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyHeavyDutyMember 		(13)us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyHeavyDutyMember 		 
Manuafacturing - Beijing Foton Cummins Engine Company (Heavy-Duty) [Member] | Minimum        
Equity, royalty and interest income from investees        
Capacity of mechanical engines (in liters)       10.5cmi_CapacityOfMechanicalEngine
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyHeavyDutyMember
Manuafacturing - Beijing Foton Cummins Engine Company (Heavy-Duty) [Member] | Maximum        
Equity, royalty and interest income from investees        
Capacity of mechanical engines (in liters)       11.8cmi_CapacityOfMechanicalEngine
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_BeijingFotonCumminsEngineCompanyHeavyDutyMember
Manufacturing - All other manufacturers        
Equity, royalty and interest income from investees        
Cummins share of net income 74us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_AllOtherManufacturersMember 		53us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_AllOtherManufacturersMember 		65us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_AllOtherManufacturersMember 		 
Manufacturing - Komatsu manufacturing alliances        
Equity, royalty and interest income from investees        
Investments and advances related to equity method investees 160us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_KomatsuManufacturingAlliancesMember 		132us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_KomatsuManufacturingAlliancesMember 		   
Manufacturing - Komatsu manufacturing alliances | Minimum        
Equity, royalty and interest income from investees        
Ownership percentage 20.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_KomatsuManufacturingAlliancesMember 		     
Manufacturing - Komatsu manufacturing alliances | Maximum        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_KomatsuManufacturingAlliancesMember 		     
Manufacturing - Cummins-Scania XPI Manufacturing, LLC        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_CumminsScaniaXPIManufacturingLLCMember 		     
Investments and advances related to equity method investees 85us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_CumminsScaniaXPIManufacturingLLCMember 		71us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_CumminsScaniaXPIManufacturingLLCMember 		   
Manufacturing - Tata Cummins, Ltd.        
Equity, royalty and interest income from investees        
Ownership percentage 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_TataCumminsLtdMember 		     
Investments and advances related to equity method investees 57us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_TataCumminsLtdMember 		50us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_TataCumminsLtdMember 		   
Other Distributors and Manufacturers        
Equity, royalty and interest income from investees        
Investments and advances related to equity method investees $ 293us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_OtherDistributorsAndManufacturersMember 		$ 259us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= cmi_OtherDistributorsAndManufacturersMember 		   
[1] Current ownership percentage of North American distributor investments as of December 31, 2014
[2] Includes both the light-duty and the heavy-duty businesses.