Financing Activities (Details 4) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	$ 27,516	$ 25,125
Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	26,907	24,653
Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	609	472
North America
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	10,218	9,923
North America | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	10,141	9,811
North America | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	77	112
Europe
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	3,329	2,960
Europe | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	3,285	2,902
Europe | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	44	58
Asia/Pacific
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	4,954	4,192
Asia/Pacific | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	4,914	4,168
Asia/Pacific | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	40	24
Mining
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	1,840	1,485
Mining | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	1,828	1,473
Mining | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	12	12
Latin America
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	3,982	3,616
Latin America | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	3,832	3,508
Latin America | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	150	108
Caterpillar Power Finance
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	3,193	2,949
Caterpillar Power Finance | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,907	2,791
Caterpillar Power Finance | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	286	158
Customer
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	19,504	17,998
Customer | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	18,895	17,526
Customer | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	609	472
Customer | North America
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	5,836	5,673
Customer | North America | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	5,759	5,561
Customer | North America | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	77	112
Customer | Europe
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,455	2,224
Customer | Europe | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,411	2,166
Customer | Europe | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	44	58
Customer | Asia/Pacific
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	3,515	3,211
Customer | Asia/Pacific | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	3,475	3,187
Customer | Asia/Pacific | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	40	24
Customer | Mining
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	1,839	1,485
Customer | Mining | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	1,827	1,473
Customer | Mining | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	12	12
Customer | Latin America
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,696	2,485
Customer | Latin America | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,546	2,377
Customer | Latin America | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	150	108
Customer | Caterpillar Power Finance
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	3,163	2,920
Customer | Caterpillar Power Finance | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,877	2,762
Customer | Caterpillar Power Finance | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	286	158
Dealer
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	5,062	3,973
Dealer | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	5,062	3,973
Dealer | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Dealer | North America
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,759	2,414
Dealer | North America | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,759	2,414
Dealer | North America | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Dealer | Europe
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	487	334
Dealer | Europe | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	487	334
Dealer | Europe | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Dealer | Asia/Pacific
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	923	516
Dealer | Asia/Pacific | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	923	516
Dealer | Asia/Pacific | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Dealer | Mining
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	1	0
Dealer | Mining | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	1	0
Dealer | Mining | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Dealer | Latin America
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	892	709
Dealer | Latin America | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	892	709
Dealer | Latin America | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Dealer | Caterpillar Power Finance
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Dealer | Caterpillar Power Finance | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Dealer | Caterpillar Power Finance | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,950	3,154
Caterpillar Purchased Receivables | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	2,950	3,154
Caterpillar Purchased Receivables | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables | North America
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	1,623	1,836
Caterpillar Purchased Receivables | North America | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	1,623	1,836
Caterpillar Purchased Receivables | North America | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables | Europe
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	387	402
Caterpillar Purchased Receivables | Europe | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	387	402
Caterpillar Purchased Receivables | Europe | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables | Asia/Pacific
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	516	465
Caterpillar Purchased Receivables | Asia/Pacific | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	516	465
Caterpillar Purchased Receivables | Asia/Pacific | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables | Mining
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables | Mining | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables | Mining | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables | Latin America
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	394	422
Caterpillar Purchased Receivables | Latin America | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	394	422
Caterpillar Purchased Receivables | Latin America | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	0	0
Caterpillar Purchased Receivables | Caterpillar Power Finance
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	30	29
Caterpillar Purchased Receivables | Caterpillar Power Finance | Performing
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	30	29
Caterpillar Purchased Receivables | Caterpillar Power Finance | Nonperforming
Recorded investment in finance receivables
Recorded Investment in Finance Receivables, Ending Balance	$ 0	$ 0