Cat Financial Financing Activities (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012 D	Dec. 31, 2011
Cat Financial Financing Activities [Abstract]
Period after which Unpaid Installments are Considered as Past Due (in days)	30
Period after which collection of future income is considered as not probable (in days)	120
Aging related to loans and finance leases
31-60 Days Past Due	$ 287	$ 194
61-90 Days Past Due	128	104
91+ Days Past Due	533	442
Total Past Due	948	740
Current	20,778	19,240
Total Finance Receivables	21,726	19,980
91+ Still Accruing	40	58
North America
Aging related to loans and finance leases
Total Finance Receivables	7,570	7,291
Europe
Aging related to loans and finance leases
Total Finance Receivables	2,388	2,281
Asia Pacific
Aging related to loans and finance leases
Total Finance Receivables	3,615	3,038
Mining
Aging related to loans and finance leases
Total Finance Receivables	1,725	1,485
Latin America
Aging related to loans and finance leases
Total Finance Receivables	3,260	2,965
Caterpillar Power Finance
Aging related to loans and finance leases
Total Finance Receivables	3,168	2,920
Customer
Aging related to loans and finance leases
Total Finance Receivables	18,448	17,593
Investment in loans and finance leases on non-accrual status	648	472
Customer | North America
Aging related to loans and finance leases
31-60 Days Past Due	41	74
61-90 Days Past Due	17	39
91+ Days Past Due	89	111
Total Past Due	147	224
Current	5,516	5,378
Total Finance Receivables	5,663	5,602
91+ Still Accruing	1	9
Investment in loans and finance leases on non-accrual status	92	112
Customer | Europe
Aging related to loans and finance leases
31-60 Days Past Due	32	27
61-90 Days Past Due	27	11
91+ Days Past Due	56	57
Total Past Due	115	95
Current	2,204	2,129
Total Finance Receivables	2,319	2,224
91+ Still Accruing	10	10
Investment in loans and finance leases on non-accrual status	48	58
Customer | Asia Pacific
Aging related to loans and finance leases
31-60 Days Past Due	82	47
61-90 Days Past Due	29	23
91+ Days Past Due	42	38
Total Past Due	153	108
Current	2,842	2,769
Total Finance Receivables	2,995	2,877
91+ Still Accruing	15	14
Investment in loans and finance leases on non-accrual status	30	24
Customer | Mining
Aging related to loans and finance leases
31-60 Days Past Due	4	0
61-90 Days Past Due	0	0
91+ Days Past Due	12	12
Total Past Due	16	12
Current	1,708	1,473
Total Finance Receivables	1,724	1,485
91+ Still Accruing	0	0
Investment in loans and finance leases on non-accrual status	12	12
Customer | Latin America
Aging related to loans and finance leases
31-60 Days Past Due	45	32
61-90 Days Past Due	23	15
91+ Days Past Due	157	99
Total Past Due	225	146
Current	2,354	2,339
Total Finance Receivables	2,579	2,485
91+ Still Accruing	0	0
Investment in loans and finance leases on non-accrual status	169	108
Customer | Caterpillar Power Finance
Aging related to loans and finance leases
31-60 Days Past Due	83	14
61-90 Days Past Due	32	16
91+ Days Past Due	177	125
Total Past Due	292	155
Current	2,876	2,765
Total Finance Receivables	3,168	2,920
91+ Still Accruing	14	25
Investment in loans and finance leases on non-accrual status	297	158
Dealer
Aging related to loans and finance leases
Total Finance Receivables	3,278	2,387
Investment in loans and finance leases on non-accrual status	0	0
Dealer | North America
Aging related to loans and finance leases
31-60 Days Past Due
61-90 Days Past Due
91+ Days Past Due
Total Past Due	0	0
Current	1,907	1,689
Total Finance Receivables	1,907	1,689
91+ Still Accruing
Dealer | Europe
Aging related to loans and finance leases
31-60 Days Past Due
61-90 Days Past Due
91+ Days Past Due
Total Past Due	0	0
Current	69	57
Total Finance Receivables	69	57
91+ Still Accruing
Dealer | Asia Pacific
Aging related to loans and finance leases
31-60 Days Past Due
61-90 Days Past Due
91+ Days Past Due
Total Past Due	0	0
Current	620	161
Total Finance Receivables	620	161
91+ Still Accruing
Dealer | Mining
Aging related to loans and finance leases
31-60 Days Past Due
61-90 Days Past Due
91+ Days Past Due
Total Past Due	0	0
Current	1	0
Total Finance Receivables	1	0
91+ Still Accruing
Dealer | Latin America
Aging related to loans and finance leases
31-60 Days Past Due
61-90 Days Past Due
91+ Days Past Due
Total Past Due	0	0
Current	681	480
Total Finance Receivables	681	480
91+ Still Accruing
Dealer | Caterpillar Power Finance
Aging related to loans and finance leases
Total Finance Receivables	$ 0	$ 0