Cat Financial Financing Activities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Cat Financial Financing Activities
Period after which collection of future income is considered as not probable (in days)			120
Customer
Impaired loans and finance leases
Recorded Investment	$ 632		$ 632		$ 575
Unpaid Principal Balance	618		618		557
Related Allowance	61		61		56
Average Recorded Investment	618	746	596	714
Interest Income Recognized	4	5	7	11
Customer | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	282		282		326
Unpaid Principal Balance	278		278		317
Related Allowance	0		0		0
Average Recorded Investment	321	397	316	355
Interest Income Recognized	1	1	3	3
Customer | Impaired Loans and Finance Leases with Allowance Recorded
Impaired loans and finance leases
Recorded Investment	350		350		249
Unpaid Principal Balance	340		340		240
Related Allowance	61		61		56
Average Recorded Investment	297	349	280	359
Interest Income Recognized	3	4	4	8
Customer | North America
Impaired loans and finance leases
Recorded Investment	104		104		152
Unpaid Principal Balance	97		97		144
Related Allowance	12		12		15
Average Recorded Investment	123	265	132	272
Interest Income Recognized	1	3	2	6
Customer | North America | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	46		46		83
Unpaid Principal Balance	44		44		80
Related Allowance	0		0		0
Average Recorded Investment	57	104	63	97
Interest Income Recognized	0	1	1	2
Customer | North America | Impaired Loans and Finance Leases with Allowance Recorded
Impaired loans and finance leases
Recorded Investment	58		58		69
Unpaid Principal Balance	53		53		64
Related Allowance	12		12		15
Average Recorded Investment	66	161	69	175
Interest Income Recognized	1	2	1	4
Customer | Europe
Impaired loans and finance leases
Recorded Investment	83		83		83
Unpaid Principal Balance	82		82		79
Related Allowance	11		11		12
Average Recorded Investment	85	61	85	65
Interest Income Recognized	0	0	0	1
Customer | Europe | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	45		45		47
Unpaid Principal Balance	44		44		46
Related Allowance	0		0		0
Average Recorded Investment	45	8	45	7
Interest Income Recognized	0	0	0	0
Customer | Europe | Impaired Loans and Finance Leases with Allowance Recorded
Impaired loans and finance leases
Recorded Investment	38		38		36
Unpaid Principal Balance	38		38		33
Related Allowance	11		11		12
Average Recorded Investment	40	53	40	58
Interest Income Recognized	0	0	0	1
Customer | Asia Pacific
Impaired loans and finance leases
Recorded Investment	31		31		17
Unpaid Principal Balance	31		31		17
Related Allowance	4		4		3
Average Recorded Investment	27	23	25	26
Interest Income Recognized	0	1	1	1
Customer | Asia Pacific | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	3		3		4
Unpaid Principal Balance	3		3		4
Related Allowance	0		0		0
Average Recorded Investment	3	6	3	5
Interest Income Recognized	0	0	0	0
Customer | Asia Pacific | Impaired Loans and Finance Leases with Allowance Recorded
Impaired loans and finance leases
Recorded Investment	28		28		13
Unpaid Principal Balance	28		28		13
Related Allowance	4		4		3
Average Recorded Investment	24	17	22	21
Interest Income Recognized	0	1	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	49	8	37	8
Interest Income Recognized	1	0	1	0
Customer | Mining | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	8		8		8
Unpaid Principal Balance	8		8		8
Related Allowance	0		0		0
Average Recorded Investment	8	8	8	8
Interest Income Recognized	0	0	0	0
Customer | Mining | Impaired Loans and Finance Leases with Allowance Recorded
Impaired loans and finance leases
Recorded Investment	69		69		13
Unpaid Principal Balance	68		68		13
Related Allowance	7		7		4
Average Recorded Investment	41	0	29	0
Interest Income Recognized	1	0	1	0
Customer | Latin America
Impaired loans and finance leases
Recorded Investment	50		50		34
Unpaid Principal Balance	50		50		34
Related Allowance	7		7		6
Average Recorded Investment	45	56	39	53
Interest Income Recognized	1	1	1	2
Customer | Latin America | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	5		5		9
Unpaid Principal Balance	5		5		9
Related Allowance	0		0		0
Average Recorded Investment	5	10	6	7
Interest Income Recognized	0	0	0	0
Customer | Latin America | Impaired Loans and Finance Leases with Allowance Recorded
Impaired loans and finance leases
Recorded Investment	45		45		25
Unpaid Principal Balance	45		45		25
Related Allowance	7		7		6
Average Recorded Investment	40	46	33	46
Interest Income Recognized	1	1	1	2
Customer | Caterpillar Power Finance
Impaired loans and finance leases
Recorded Investment	287		287		268
Unpaid Principal Balance	282		282		262
Related Allowance	20		20		16
Average Recorded Investment	289	333	278	290
Interest Income Recognized	1	0	2	1
Customer | Caterpillar Power Finance | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	175		175		175
Unpaid Principal Balance	174		174		170
Related Allowance	0		0		0
Average Recorded Investment	203	261	191	231
Interest Income Recognized	1	0	2	1
Customer | Caterpillar Power Finance | Impaired Loans and Finance Leases with Allowance Recorded
Impaired loans and finance leases
Recorded Investment	112		112		93
Unpaid Principal Balance	108		108		92
Related Allowance	20		20		16
Average Recorded Investment	86	72	87	59
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