Cat Financial Financing Activities (Details 4) - Finance Receivables - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	$ 805	$ 679
Current	21,827	21,718
Total	22,632	22,397
91 Days or More Past Due and Still Accruing	36	18
31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	165	137
61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	192	79
91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	448	463
Customer
Aging related to loans and finance leases
Total	19,168	19,022
Customer | North America
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	128	125
Current	7,950	7,938
Total	8,078	8,063
91 Days or More Past Due and Still Accruing	8	5
Customer | North America | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	71	50
Customer | North America | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	15	16
Customer | North America | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	42	59
Customer | Europe
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	77	67
Current	2,718	2,388
Total	2,795	2,455
91 Days or More Past Due and Still Accruing	13	6
Customer | Europe | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	21	16
Customer | Europe | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	10	12
Customer | Europe | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	46	39
Customer | Asia Pacific
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	34	39
Current	2,009	1,435
Total	2,043	1,474
91 Days or More Past Due and Still Accruing	5	4
Customer | Asia Pacific | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	13	17
Customer | Asia Pacific | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	7	7
Customer | Asia Pacific | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	14	15
Customer | Mining
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	64	68
Current	1,751	1,756
Total	1,815	1,824
91 Days or More Past Due and Still Accruing	9	2
Customer | Mining | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	3	3
Customer | Mining | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	1	2
Customer | Mining | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	60	63
Customer | Latin America
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	234	287
Current	1,531	1,808
Total	1,765	2,095
91 Days or More Past Due and Still Accruing	0	0
Customer | Latin America | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	37	40
Customer | Latin America | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	55	33
Customer | Latin America | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	142	214
Customer | Caterpillar Power Finance
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	196	93
Current	2,476	3,018
Total	2,672	3,111
91 Days or More Past Due and Still Accruing	1	1
Customer | Caterpillar Power Finance | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	20	11
Customer | Caterpillar Power Finance | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	32	9
Customer | Caterpillar Power Finance | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	144	73
Dealer
Aging related to loans and finance leases
Total	3,464	3,375
Dealer | North America
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	1,920	1,916
Total	1,920	1,916
91 Days or More Past Due and Still Accruing	0	0
Dealer | North America | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | North America | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | North America | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Europe
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	222	161
Total	222	161
91 Days or More Past Due and Still Accruing	0	0
Dealer | Europe | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Europe | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Europe | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Asia Pacific
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	553	541
Total	553	541
91 Days or More Past Due and Still Accruing	0	0
Dealer | Asia Pacific | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Asia Pacific | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Asia Pacific | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Mining
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	4	3
Total	4	3
91 Days or More Past Due and Still Accruing	0	0
Dealer | Mining | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Mining | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Mining | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Latin America
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	72	0
Current	691	752
Total	763	752
91 Days or More Past Due and Still Accruing	0	0
Dealer | Latin America | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Latin America | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	72	0
Dealer | Latin America | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Caterpillar Power Finance
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	2	2
Total	2	2
91 Days or More Past Due and Still Accruing	0	0
Dealer | Caterpillar Power Finance | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Caterpillar Power Finance | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Dealer | Caterpillar Power Finance | 91 Days or More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	$ 0	$ 0