Cat Financial Financing Activities (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Receivables [Abstract]
Period after which finance receivables are considered non-performing (in days)	120 days
Finance Receivables
Ending balance-recorded investment in finance receivables	$ 23,573	$ 23,308
Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	23,056	22,795
Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	517	513
North America
Finance Receivables
Ending balance-recorded investment in finance receivables	8,072	8,030
North America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	8,024	7,971
North America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	48	59
Europe
Finance Receivables
Ending balance-recorded investment in finance receivables	2,679	2,740
Europe | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,638	2,702
Europe | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	41	38
Asia Pacific
Finance Receivables
Ending balance-recorded investment in finance receivables	3,773	3,789
Asia Pacific | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3,720	3,753
Asia Pacific | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	53	36
Mining
Finance Receivables
Ending balance-recorded investment in finance receivables	2,120	1,974
Mining | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,108	1,962
Mining | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	12	12
Latin America
Finance Receivables
Ending balance-recorded investment in finance receivables	3,716	3,603
Latin America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3,549	3,455
Latin America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	167	148
Caterpillar Power Finance
Finance Receivables
Ending balance-recorded investment in finance receivables	3,213	3,172
Caterpillar Power Finance | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3,017	2,952
Caterpillar Power Finance | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	196	220
Customer
Finance Receivables
Ending balance-recorded investment in finance receivables	19,694	19,424
Customer | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	19,177	18,911
Customer | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	517	513
Customer | North America
Finance Receivables
Ending balance-recorded investment in finance receivables	5,983	5,967
Customer | North America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	5,935	5,908
Customer | North America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	48	59
Customer | Europe
Finance Receivables
Ending balance-recorded investment in finance receivables	2,501	2,555
Customer | Europe | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,460	2,517
Customer | Europe | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	41	38
Customer | Asia Pacific
Finance Receivables
Ending balance-recorded investment in finance receivables	3,021	3,038
Customer | Asia Pacific | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,968	3,002
Customer | Asia Pacific | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	53	36
Customer | Mining
Finance Receivables
Ending balance-recorded investment in finance receivables	2,119	1,973
Customer | Mining | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,107	1,961
Customer | Mining | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	12	12
Customer | Latin America
Finance Receivables
Ending balance-recorded investment in finance receivables	2,857	2,719
Customer | Latin America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,690	2,571
Customer | Latin America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	167	148
Customer | Caterpillar Power Finance
Finance Receivables
Ending balance-recorded investment in finance receivables	3,213	3,172
Customer | Caterpillar Power Finance | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3,017	2,952
Customer | Caterpillar Power Finance | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	196	220
Dealer
Finance Receivables
Ending balance-recorded investment in finance receivables	3,879	3,884
Dealer | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3,879	3,884
Dealer | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Dealer | North America
Finance Receivables
Ending balance-recorded investment in finance receivables	2,089	2,063
Dealer | North America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,089	2,063
Dealer | North America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables
Dealer | Europe
Finance Receivables
Ending balance-recorded investment in finance receivables	178	185
Dealer | Europe | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	178	185
Dealer | Europe | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables
Dealer | Asia Pacific
Finance Receivables
Ending balance-recorded investment in finance receivables	752	751
Dealer | Asia Pacific | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	752	751
Dealer | Asia Pacific | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables
Dealer | Mining
Finance Receivables
Ending balance-recorded investment in finance receivables	1	1
Dealer | Mining | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	1	1
Dealer | Mining | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables
Dealer | Latin America
Finance Receivables
Ending balance-recorded investment in finance receivables	859	884
Dealer | Latin America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	859	884
Dealer | Latin America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables
Dealer | Caterpillar Power Finance
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Dealer | Caterpillar Power Finance | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Dealer | Caterpillar Power Finance | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables