Finance Receivables (Details 6) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) contracts	Sep. 30, 2017 USD ($) contracts	Sep. 30, 2018 USD ($) contracts	Sep. 30, 2017 USD ($) contracts	Dec. 31, 2017 USD ($)
Financing Receivable, Modifications
Remaining commitments	$ 0		$ 0		$ 0
Finance receivables modified as TDRs
Number of Contracts | contracts	6	20	43	123
Pre-TDR Recorded Investment	$ 40	$ 76	$ 138	$ 454
Post-TDR Recorded Investment	$ 40	$ 71	$ 105	$ 431
Customer
TDRs which had been modified within twelve months of the default date
Number of contracts | contracts	11	1	16	241
Post-TDR Recorded Investment	$ 42	$ 0	$ 44	$ 16
Customer | North America
Finance receivables modified as TDRs
Number of Contracts | contracts	4	11	34	37
Pre-TDR Recorded Investment	$ 0	$ 4	$ 13	$ 13
Post-TDR Recorded Investment	$ 0	$ 5	$ 13	$ 13
TDRs which had been modified within twelve months of the default date
Number of contracts | contracts	7	0	10	0
Post-TDR Recorded Investment	$ 9	$ 0	$ 10	$ 0
Customer | Europe
Finance receivables modified as TDRs
Number of Contracts | contracts	0	1	0	2
Pre-TDR Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post-TDR Recorded Investment	$ 0	$ 0	$ 0	$ 0
Customer | Asia/Pacific
Finance receivables modified as TDRs
Number of Contracts | contracts			0	6
Pre-TDR Recorded Investment			$ 0	$ 39
Post-TDR Recorded Investment			$ 0	$ 30
Customer | Mining
Finance receivables modified as TDRs
Number of Contracts | contracts			1	2
Pre-TDR Recorded Investment			$ 29	$ 57
Post-TDR Recorded Investment			$ 29	$ 56
Customer | Latin America
Finance receivables modified as TDRs
Number of Contracts | contracts	0	3	1	17
Pre-TDR Recorded Investment	$ 0	$ 21	$ 3	$ 26
Post-TDR Recorded Investment	$ 0	$ 22	$ 3	$ 27
TDRs which had been modified within twelve months of the default date
Number of contracts | contracts	1	1	3	241
Post-TDR Recorded Investment	$ 0	$ 0	$ 1	$ 16
Customer | Caterpillar Power Finance
Finance receivables modified as TDRs
Number of Contracts | contracts	2	5	7	59
Pre-TDR Recorded Investment	$ 40	$ 51	$ 93	$ 319
Post-TDR Recorded Investment	$ 40	$ 44	$ 60	$ 305
TDRs which had been modified within twelve months of the default date
Number of contracts | contracts	3	0	3	0
Post-TDR Recorded Investment	$ 33	$ 0	$ 33	$ 0
Dealer
Finance receivables modified as TDRs
Number of Contracts | contracts	0	0	0	0
Caterpillar Purchased Receivables
Finance receivables modified as TDRs
Number of Contracts | contracts	0	0	0	0
Significant Amount of Amount Disclosed Represented by a Certain Number of Customers (Four) [Member] | Customer | Caterpillar Power Finance
Finance receivables modified as TDRs
Number of Contracts | contracts				44
Pre-TDR Recorded Investment				$ 200
Post-TDR Recorded Investment				$ 200