Cat Financial Financing Activities (Details 4) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Receivables [Abstract]
Period after which finance receivables are considered non-performing (in days)	120 days
Finance Receivables
Ending balance-recorded investment in finance receivables	$ 22,739	$ 24,066
Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	22,131	23,598
Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	608	468
North America
Finance Receivables
Ending balance-recorded investment in finance receivables	9,938	9,462
North America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	9,908	9,435
North America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	30	27
Europe
Finance Receivables
Ending balance-recorded investment in finance receivables	2,636	2,828
Europe | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,590	2,800
Europe | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	46	28
Asia Pacific
Finance Receivables
Ending balance-recorded investment in finance receivables	2,372	3,002
Asia Pacific | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,347	2,948
Asia Pacific | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	25	54
Mining
Finance Receivables
Ending balance-recorded investment in finance receivables	1,852	2,123
Mining | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	1,719	2,061
Mining | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	133	62
Latin America
Finance Receivables
Ending balance-recorded investment in finance receivables	2,766	3,503
Latin America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,506	3,302
Latin America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	260	201
Caterpillar Power Finance
Finance Receivables
Ending balance-recorded investment in finance receivables	3,175	3,148
Caterpillar Power Finance | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3,061	3,052
Caterpillar Power Finance | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	114	96
Dealer
Finance Receivables
Ending balance-recorded investment in finance receivables	3,523	3,554
Dealer | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3,523	3,554
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	2,283	2,189
Dealer | North America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,283	2,189
Dealer | North America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Dealer | Europe
Finance Receivables
Ending balance-recorded investment in finance receivables	149	153
Dealer | Europe | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	149	153
Dealer | Europe | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Dealer | Asia Pacific
Finance Receivables
Ending balance-recorded investment in finance receivables	525	566
Dealer | Asia Pacific | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	525	566
Dealer | Asia Pacific | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Dealer | Mining
Finance Receivables
Ending balance-recorded investment in finance receivables	4	0
Dealer | Mining | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	4	0
Dealer | Mining | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Dealer | Latin America
Finance Receivables
Ending balance-recorded investment in finance receivables	559	646
Dealer | Latin America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	559	646
Dealer | Latin America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Dealer | Caterpillar Power Finance
Finance Receivables
Ending balance-recorded investment in finance receivables	3	0
Dealer | Caterpillar Power Finance | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3	0
Dealer | Caterpillar Power Finance | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	0	0
Customer
Finance Receivables
Ending balance-recorded investment in finance receivables	19,216	20,512
Customer | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	18,608	20,044
Customer | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	608	468
Customer | North America
Finance Receivables
Ending balance-recorded investment in finance receivables	7,655	7,273
Customer | North America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	7,625	7,246
Customer | North America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	30	27
Customer | Europe
Finance Receivables
Ending balance-recorded investment in finance receivables	2,487	2,675
Customer | Europe | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	2,441	2,647
Customer | Europe | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	46	28
Customer | Asia Pacific
Finance Receivables
Ending balance-recorded investment in finance receivables	1,847	2,436
Customer | Asia Pacific | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	1,822	2,382
Customer | Asia Pacific | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	25	54
Customer | Mining
Finance Receivables
Ending balance-recorded investment in finance receivables	1,848	2,123
Customer | Mining | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	1,715	2,061
Customer | Mining | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	133	62
Customer | Latin America
Finance Receivables
Ending balance-recorded investment in finance receivables	2,207	2,857
Customer | Latin America | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	1,947	2,656
Customer | Latin America | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	260	201
Customer | Caterpillar Power Finance
Finance Receivables
Ending balance-recorded investment in finance receivables	3,172	3,148
Customer | Caterpillar Power Finance | Performing
Finance Receivables
Ending balance-recorded investment in finance receivables	3,058	3,052
Customer | Caterpillar Power Finance | Nonperforming
Finance Receivables
Ending balance-recorded investment in finance receivables	$ 114	$ 96