Cat Financial Financing Activities (Details 3) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Dealer
Impaired finance receivables
Recorded Investment, Total	$ 0		$ 0		$ 0
Finance Receivables \| Customer
Impaired finance receivables
Recorded Investment With No Allowance Recorded	173		173		424
Unpaid Principal Balance With No Allowance Recorded	185		185		435
Related Allowance With No Allowance Recorded	0		0		0
Recorded Investment With An Allowance Recorded	629		629		518
Unpaid Principal Balance With An Allowance Recorded	634		634		530
Related Allowance With An Allowance Recorded	229		229		149
Recorded Investment, Total	802		802		942
Unpaid Principal Balance, Total	819		819		965
Related Allowance, Total	229		229		149
Average Recorded Investment With No Allowance Recorded	218	$ 458	319	$ 512
Interest Income Recognized With No Allowance Recorded	4	5	12	18
Average Recorded Investment With An Allowance Recorded	593	431	572	335
Interest Income Recognized With An Allowance Recorded	6	5	15	10
Average Recorded Investment, Total	811	889	891	847
Interest Income Recognized, Total	10	10	27	28
Finance Receivables \| Customer \| North America
Impaired finance receivables
Recorded Investment With No Allowance Recorded	17		17		19
Unpaid Principal Balance With No Allowance Recorded	17		17		19
Related Allowance With No Allowance Recorded	0		0		0
Recorded Investment With An Allowance Recorded	41		41		44
Unpaid Principal Balance With An Allowance Recorded	39		39		43
Related Allowance With An Allowance Recorded	18		18		17
Recorded Investment, Total	58		58		63
Unpaid Principal Balance, Total	56		56		62
Related Allowance, Total	18		18		17
Average Recorded Investment With No Allowance Recorded	19	14	17	12
Interest Income Recognized With No Allowance Recorded	0	1	1	1
Average Recorded Investment With An Allowance Recorded	47	44	51	52
Interest Income Recognized With An Allowance Recorded	0	0	1	1
Average Recorded Investment, Total	66	58	68	64
Interest Income Recognized, Total	0	1	2	2
Finance Receivables \| Customer \| Europe
Impaired finance receivables
Recorded Investment With No Allowance Recorded	2		2		45
Unpaid Principal Balance With No Allowance Recorded	1		1		45
Related Allowance With No Allowance Recorded	0		0		0
Recorded Investment With An Allowance Recorded	66		66		9
Unpaid Principal Balance With An Allowance Recorded	66		66		8
Related Allowance With An Allowance Recorded	36		36		5
Recorded Investment, Total	68		68		54
Unpaid Principal Balance, Total	67		67		53
Related Allowance, Total	36		36		5
Average Recorded Investment With No Allowance Recorded	4	47	17	48
Interest Income Recognized With No Allowance Recorded	0	0	0	1
Average Recorded Investment With An Allowance Recorded	59	6	41	6
Interest Income Recognized With An Allowance Recorded	0	0	1	0
Average Recorded Investment, Total	63	53	58	54
Interest Income Recognized, Total	0	0	1	1
Finance Receivables \| Customer \| Asia Pacific
Impaired finance receivables
Recorded Investment With No Allowance Recorded	28		28		34
Unpaid Principal Balance With No Allowance Recorded	28		28		33
Related Allowance With No Allowance Recorded	0		0		0
Recorded Investment With An Allowance Recorded	2		2		8
Unpaid Principal Balance With An Allowance Recorded	2		2		8
Related Allowance With An Allowance Recorded	1		1		2
Recorded Investment, Total	30		30		42
Unpaid Principal Balance, Total	30		30		41
Related Allowance, Total	1		1		2
Average Recorded Investment With No Allowance Recorded	29	30	30	22
Interest Income Recognized With No Allowance Recorded	1	1	2	2
Average Recorded Investment With An Allowance Recorded	2	28	4	35
Interest Income Recognized With An Allowance Recorded	0	1	0	2
Average Recorded Investment, Total	31	58	34	57
Interest Income Recognized, Total	1	2	2	4
Finance Receivables \| Customer \| Mining
Impaired finance receivables
Recorded Investment With No Allowance Recorded	34		34		121
Unpaid Principal Balance With No Allowance Recorded	34		34		121
Related Allowance With No Allowance Recorded	0		0		0
Recorded Investment With An Allowance Recorded	58		58		0
Unpaid Principal Balance With An Allowance Recorded	58		58		0
Related Allowance With An Allowance Recorded	22		22		0
Recorded Investment, Total	92		92		121
Unpaid Principal Balance, Total	92		92		121
Related Allowance, Total	22		22		0
Average Recorded Investment With No Allowance Recorded	35	128	65	128
Interest Income Recognized With No Allowance Recorded	0	1	2	5
Average Recorded Investment With An Allowance Recorded	60	0	43	0
Interest Income Recognized With An Allowance Recorded	1	0	2	0
Average Recorded Investment, Total	95	128	108	128
Interest Income Recognized, Total	1	1	4	5
Finance Receivables \| Customer \| Latin America
Impaired finance receivables
Recorded Investment With No Allowance Recorded	31		31		45
Unpaid Principal Balance With No Allowance Recorded	31		31		45
Related Allowance With No Allowance Recorded	0		0		0
Recorded Investment With An Allowance Recorded	61		61		95
Unpaid Principal Balance With An Allowance Recorded	61		61		106
Related Allowance With An Allowance Recorded	34		34		42
Recorded Investment, Total	92		92		140
Unpaid Principal Balance, Total	92		92		151
Related Allowance, Total	34		34		42
Average Recorded Investment With No Allowance Recorded	37	68	41	69
Interest Income Recognized With No Allowance Recorded	1	1	2	2
Average Recorded Investment With An Allowance Recorded	51	102	69	101
Interest Income Recognized With An Allowance Recorded	1	1	3	3
Average Recorded Investment, Total	88	170	110	170
Interest Income Recognized, Total	2	2	5	5
Finance Receivables \| Customer \| Caterpillar Power Finance
Impaired finance receivables
Recorded Investment With No Allowance Recorded	61		61		160
Unpaid Principal Balance With No Allowance Recorded	74		74		172
Related Allowance With No Allowance Recorded	0		0		0
Recorded Investment With An Allowance Recorded	401		401		362
Unpaid Principal Balance With An Allowance Recorded	408		408		365
Related Allowance With An Allowance Recorded	118		118		83
Recorded Investment, Total	462		462		522
Unpaid Principal Balance, Total	482		482		537
Related Allowance, Total	118		118		$ 83
Average Recorded Investment With No Allowance Recorded	94	171	149	233
Interest Income Recognized With No Allowance Recorded	2	1	5	7
Average Recorded Investment With An Allowance Recorded	374	251	364	141
Interest Income Recognized With An Allowance Recorded	4	3	8	4
Average Recorded Investment, Total	468	422	513	374
Interest Income Recognized, Total	$ 6	$ 4	$ 13	$ 11

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