Financing Activities (Details 2) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Receivables [Abstract]
Period after which unpaid installments are considered as past due	30 days
Period after which collection of future income is considered as not probable	120 days
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	$ 241	$ 224
61-90 Days Past Due	121	108
Greater than 91 Days Past Due	474	450
Total Past Due	836	782
Current	26,680	24,343
Total gross finance receivables	27,516	25,125
Greater than 91, Still Accruing	35	66
Investment in loans and finance leases on non-accrual status	609	472
North America
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	10,218	9,923
Europe
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	3,329	2,960
Asia/Pacific
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	4,954	4,192
Mining
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	1,840	1,485
Latin America
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	3,982	3,616
Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	3,193	2,949
Customer
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	19,504	17,998
Customer | North America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	35	75
61-90 Days Past Due	9	39
Greater than 91 Days Past Due	76	111
Total Past Due	120	225
Current	5,716	5,448
Total gross finance receivables	5,836	5,673
Greater than 91, Still Accruing	0	9
Investment in loans and finance leases on non-accrual status	77	112
Customer | Europe
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	28	27
61-90 Days Past Due	12	11
Greater than 91 Days Past Due	44	57
Total Past Due	84	95
Current	2,371	2,129
Total gross finance receivables	2,455	2,224
Greater than 91, Still Accruing	5	10
Investment in loans and finance leases on non-accrual status	44	58
Customer | Asia/Pacific
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	76	48
61-90 Days Past Due	22	23
Greater than 91 Days Past Due	51	38
Total Past Due	149	109
Current	3,366	3,102
Total gross finance receivables	3,515	3,211
Greater than 91, Still Accruing	17	14
Investment in loans and finance leases on non-accrual status	40	24
Customer | Mining
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	2	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	12	12
Total Past Due	14	12
Current	1,825	1,473
Total gross finance receivables	1,839	1,485
Greater than 91, Still Accruing	0	0
Investment in loans and finance leases on non-accrual status	12	12
Customer | Latin America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	57	32
61-90 Days Past Due	25	15
Greater than 91 Days Past Due	136	99
Total Past Due	218	146
Current	2,478	2,339
Total gross finance receivables	2,696	2,485
Greater than 91, Still Accruing	0	0
Investment in loans and finance leases on non-accrual status	150	108
Customer | Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	17	14
61-90 Days Past Due	47	16
Greater than 91 Days Past Due	154	125
Total Past Due	218	155
Current	2,945	2,765
Total gross finance receivables	3,163	2,920
Greater than 91, Still Accruing	12	25
Investment in loans and finance leases on non-accrual status	286	158
Dealer
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	5,062	3,973
Investment in loans and finance leases on non-accrual status	0	0
Dealer | North America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	2
Total Past Due	0	2
Current	2,759	2,412
Total gross finance receivables	2,759	2,414
Greater than 91, Still Accruing	0	2
Dealer | Europe
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	0	0
Current	487	334
Total gross finance receivables	487	334
Greater than 91, Still Accruing	0	0
Dealer | Asia/Pacific
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	0	0
Current	923	516
Total gross finance receivables	923	516
Greater than 91, Still Accruing	0	0
Dealer | Mining
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	0	0
Current	1	0
Total gross finance receivables	1	0
Greater than 91, Still Accruing	0	0
Dealer | Latin America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	0	0
Current	892	709
Total gross finance receivables	892	709
Greater than 91, Still Accruing	0	0
Dealer | Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	0	0
Current	0	0
Total gross finance receivables	0	0
Greater than 91, Still Accruing	0	0
Caterpillar Purchased Receivables
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	2,950	3,154
Investment in loans and finance leases on non-accrual status	0	0
Caterpillar Purchased Receivables | North America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	20	25
61-90 Days Past Due	5	4
Greater than 91 Days Past Due	1	6
Total Past Due	26	35
Current	1,597	1,801
Total gross finance receivables	1,623	1,836
Greater than 91, Still Accruing	1	6
Caterpillar Purchased Receivables | Europe
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	1	3
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	1	3
Current	386	399
Total gross finance receivables	387	402
Greater than 91, Still Accruing	0	0
Caterpillar Purchased Receivables | Asia/Pacific
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	0	0
Current	516	465
Total gross finance receivables	516	465
Greater than 91, Still Accruing	0	0
Caterpillar Purchased Receivables | Mining
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	0	0
Current	0	0
Total gross finance receivables	0	0
Greater than 91, Still Accruing	0	0
Caterpillar Purchased Receivables | Latin America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 91 Days Past Due	0	0
Total Past Due	0	0
Current	394	422
Total gross finance receivables	394	422
Greater than 91, Still Accruing	0	0
Caterpillar Purchased Receivables | Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	5	0
61-90 Days Past Due	1	0
Greater than 91 Days Past Due	0	0
Total Past Due	6	0
Current	24	29
Total gross finance receivables	30	29
Greater than 91, Still Accruing	$ 0	$ 0