Cat Financial Financing Activities (Details 2) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Aging related to loans and finance leases
Finance receivables held-for-sale	$ 240
Finance Receivables
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	929	$ 805
Current	21,689	21,827
Ending balance-recorded investment in finance receivables	22,618	22,632
91+ Still Accruing	82	36
Finance Receivables | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	214	165
Finance Receivables | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	119	192
Finance Receivables | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	596	448
Finance Receivables | Customer
Aging related to loans and finance leases
Ending balance-recorded investment in finance receivables	19,163	19,168
Finance Receivables | Customer | North America
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	131	128
Current	8,067	7,950
Ending balance-recorded investment in finance receivables	8,198	8,078
91+ Still Accruing	7	8
Finance Receivables | Customer | North America | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	72	71
Finance Receivables | Customer | North America | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	16	15
Finance Receivables | Customer | North America | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	43	42
Finance Receivables | Customer | Europe
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	149	77
Current	2,659	2,718
Ending balance-recorded investment in finance receivables	2,808	2,795
91+ Still Accruing	42	13
Finance Receivables | Customer | Europe | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	31	21
Finance Receivables | Customer | Europe | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	12	10
Finance Receivables | Customer | Europe | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	106	46
Finance Receivables | Customer | Asia Pacific
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	50	34
Current	2,415	2,009
Ending balance-recorded investment in finance receivables	2,465	2,043
91+ Still Accruing	3	5
Finance Receivables | Customer | Asia Pacific | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	30	13
Finance Receivables | Customer | Asia Pacific | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	12	7
Finance Receivables | Customer | Asia Pacific | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	8	14
Finance Receivables | Customer | Mining
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	12	64
Current	1,631	1,751
Ending balance-recorded investment in finance receivables	1,643	1,815
91+ Still Accruing	0	9
Finance Receivables | Customer | Mining | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	2	3
Finance Receivables | Customer | Mining | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	1
Finance Receivables | Customer | Mining | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	10	60
Finance Receivables | Customer | Latin America
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	161	234
Current	1,408	1,531
Ending balance-recorded investment in finance receivables	1,569	1,765
91+ Still Accruing	0	0
Finance Receivables | Customer | Latin America | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	42	37
Finance Receivables | Customer | Latin America | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	17	55
Finance Receivables | Customer | Latin America | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	102	142
Finance Receivables | Customer | Caterpillar Power Finance
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	348	196
Current	2,132	2,476
Ending balance-recorded investment in finance receivables	2,480	2,672
91+ Still Accruing	30	1
Finance Receivables | Customer | Caterpillar Power Finance | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	37	20
Finance Receivables | Customer | Caterpillar Power Finance | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	61	32
Finance Receivables | Customer | Caterpillar Power Finance | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	250	144
Finance Receivables | Dealer
Aging related to loans and finance leases
Ending balance-recorded investment in finance receivables	3,455	3,464
Finance Receivables | Dealer | North America
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	1,931	1,920
Ending balance-recorded investment in finance receivables	1,931	1,920
91+ Still Accruing	0	0
Finance Receivables | Dealer | North America | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | North America | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | North America | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Europe
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	324	222
Ending balance-recorded investment in finance receivables	324	222
91+ Still Accruing	0	0
Finance Receivables | Dealer | Europe | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Europe | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Europe | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Asia Pacific
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	485	553
Ending balance-recorded investment in finance receivables	485	553
91+ Still Accruing	0	0
Finance Receivables | Dealer | Asia Pacific | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Asia Pacific | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Asia Pacific | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Mining
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	3	4
Ending balance-recorded investment in finance receivables	3	4
91+ Still Accruing	0	0
Finance Receivables | Dealer | Mining | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Mining | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Mining | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Latin America
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	78	72
Current	632	691
Ending balance-recorded investment in finance receivables	710	763
91+ Still Accruing	0	0
Finance Receivables | Dealer | Latin America | 31 to 60 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Finance Receivables | Dealer | Latin America | 61 to 90 Days Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	1	72
Finance Receivables | Dealer | Latin America | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	77	0
Finance Receivables | Dealer | Caterpillar Power Finance
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	0	0
Current	2	2
Ending balance-recorded investment in finance receivables	2	2
91+ Still Accruing	0	0
Finance Receivables | 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
Finance Receivables | 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
Finance Receivables | Dealer | Caterpillar Power Finance | 91 Days of More Past Due
Aging related to loans and finance leases
Financing Receivable, Recorded Investment, Past Due	$ 0	$ 0