Credit Commitments (Details) $ in Millions	6 Months Ended	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Line of Credit Facility
Number of global credit facilities	3	3
Caterpillar's consolidated net worth	$ 14,070	$ 14,070
Minimum net worth required under the Credit Facility	$ 9,000	$ 9,000
Covenant interest coverage ratio, Numerator		1.56
Covenant interest coverage ratio, Denominator		1
Minimum interest coverage ratio, required by the Credit Facility, Numerator		1.15
Minimum interest coverage ratio, required by the Credit Facility, Denominator		1
Leverage Ratio, Numerator	7.69	8.33
Leverage Ratio, Denominator	1	1
Maximum Leverage Ratio, Permissible Under Credit Facility, Numerator		10
Maximum Leverage Ratio, Permissible Under Credit Facility, Denominator		1
Amount available	$ 10,500	$ 10,500
Short-term borrowings, Balance	5,723	5,723	$ 4,836
Maximum borrowing capacity from Caterpillar, Variable lending agreements	2,750	2,750
Maximum lending capacity to Caterpillar, Variable lending agreements	2,140	$ 2,140
Term lending agreements, maximum remaining maturity		10 years
Notes receivable from Caterpillar	662	$ 662	559	$ 530
Notes payable to Caterpillar	1,518	1,518	1,638	$ 1,637
Amount available, Committed credit facility extended to Caterpillar	2,000	2,000
Amount outstanding, Committed credit facility extended to Caterpillar	0	0
Revolving credit facilities
Line of Credit Facility
Amount outstanding	0	0
Revolving credit facilities | Cat Financial
Line of Credit Facility
Amount available	7,750	7,750
364-day facility
Line of Credit Facility
Amount available	3,150	3,150
364-day facility | Cat Financial
Line of Credit Facility
Amount available	2,330	2,330
Three-year facility
Line of Credit Facility
Amount available	2,730	2,730
Three-year facility | Cat Financial
Line of Credit Facility
Amount available	2,010	2,010
Five-year facility
Line of Credit Facility
Amount available	4,620	4,620
Five-year facility | Cat Financial
Line of Credit Facility
Amount available	3,410	3,410
Credit lines with banks
Line of Credit Facility
Amount available	4,580	4,580
Amount outstanding	1,170	1,170	1,480
Variable denomination floating rate demand notes
Line of Credit Facility
Short-term borrowings, Balance	438	438	$ 481
Maximum amount of variable denomination floating rate demand notes outstanding	$ 1,250	$ 1,250