Cat Financial Financing Activities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Receivables [Abstract]
Period after which collection of future income is considered as not probable (in days)			120 days
Customer
Impaired loans and finance leases
Recorded Investment	$ 730		$ 730		$ 575
Unpaid Principal Balance	719		719		557
Related Allowance	75		75		56
Average Recorded Investment	685	720	628	714
Interest Income Recognized	5	3	12	14
Customer | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	375		375		326
Unpaid Principal Balance	373		373		317
Related Allowance	0		0		0
Average Recorded Investment	325	365	322	356
Interest Income Recognized	2	2	5	5
Customer | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	355		355		249
Unpaid Principal Balance	346		346		240
Related Allowance	75		75		56
Average Recorded Investment	360	355	306	358
Interest Income Recognized	3	1	7	9
Customer | North America
Impaired loans and finance leases
Recorded Investment	80		80		152
Unpaid Principal Balance	75		75		144
Related Allowance	9		9		15
Average Recorded Investment	93	217	119	253
Interest Income Recognized	1	1	3	7
Customer | North America | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	42		42		83
Unpaid Principal Balance	41		41		80
Related Allowance	0		0		0
Average Recorded Investment	42	91	56	93
Interest Income Recognized	1	1	2	3
Customer | North America | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	38		38		69
Unpaid Principal Balance	34		34		64
Related Allowance	9		9		15
Average Recorded Investment	51	126	63	160
Interest Income Recognized	0	0	1	4
Customer | Europe
Impaired loans and finance leases
Recorded Investment	94		94		83
Unpaid Principal Balance	92		92		79
Related Allowance	17		17		12
Average Recorded Investment	89	54	87	61
Interest Income Recognized	1	1	1	2
Customer | Europe | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	44		44		47
Unpaid Principal Balance	44		44		46
Related Allowance	0		0		0
Average Recorded Investment	45	10	45	8
Interest Income Recognized	0	0	0	0
Customer | Europe | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	50		50		36
Unpaid Principal Balance	48		48		33
Related Allowance	17		17		12
Average Recorded Investment	44	44	42	53
Interest Income Recognized	1	1	1	2
Customer | Asia Pacific
Impaired loans and finance leases
Recorded Investment	38		38		17
Unpaid Principal Balance	38		38		17
Related Allowance	7		7		3
Average Recorded Investment	32	14	27	23
Interest Income Recognized	0	1	1	2
Customer | Asia Pacific | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	4		4		4
Unpaid Principal Balance	4		4		4
Related Allowance	0		0		0
Average Recorded Investment	3	5	3	5
Interest Income Recognized	0	1	0	1
Customer | Asia Pacific | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	34		34		13
Unpaid Principal Balance	34		34		13
Related Allowance	7		7		3
Average Recorded Investment	29	9	24	18
Interest Income Recognized	0	0	1	1
Customer | Mining
Impaired loans and finance leases
Recorded Investment	77		77		21
Unpaid Principal Balance	76		76		21
Related Allowance	7		7		4
Average Recorded Investment	77	18	49	12
Interest Income Recognized	1	0	2	0
Customer | Mining | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	9		9		8
Unpaid Principal Balance	9		9		8
Related Allowance	0		0		0
Average Recorded Investment	9	8	8	8
Interest Income Recognized	0	0	0	0
Customer | Mining | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	68		68		13
Unpaid Principal Balance	67		67		13
Related Allowance	7		7		4
Average Recorded Investment	68	10	41	4
Interest Income Recognized	1	0	2	0
Customer | Latin America
Impaired loans and finance leases
Recorded Investment	60		60		34
Unpaid Principal Balance	60		60		34
Related Allowance	17		17		6
Average Recorded Investment	64	51	48	52
Interest Income Recognized	1	0	2	2
Customer | Latin America | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	7		7		9
Unpaid Principal Balance	7		7		9
Related Allowance	0		0		0
Average Recorded Investment	6	11	6	8
Interest Income Recognized	0	0	0	0
Customer | Latin America | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	53		53		25
Unpaid Principal Balance	53		53		25
Related Allowance	17		17		6
Average Recorded Investment	58	40	42	44
Interest Income Recognized	1	0	2	2
Customer | Caterpillar Power Finance
Impaired loans and finance leases
Recorded Investment	381		381		268
Unpaid Principal Balance	378		378		262
Related Allowance	18		18		16
Average Recorded Investment	330	366	298	313
Interest Income Recognized	1	0	3	1
Customer | Caterpillar Power Finance | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	269		269		175
Unpaid Principal Balance	268		268		170
Related Allowance	0		0		0
Average Recorded Investment	220	240	204	234
Interest Income Recognized	1	0	3	1
Customer | Caterpillar Power Finance | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	112		112		93
Unpaid Principal Balance	110		110		92
Related Allowance	18		18		16
Average Recorded Investment	110	126	94	79
Interest Income Recognized	0	0	0	0
Dealer
Impaired loans and finance leases
Recorded Investment	0		0		0
Average Recorded Investment	$ 0	$ 0	$ 0	$ 0