Financing Activities (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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	$ 208	$ 258	$ 206
61-90 Days Past Due	91	134	73
91 Plus Days Past Due	403	384	436
Total Past Due	702	776	715
Current	28,773	28,290	27,853
Total gross finance receivables	29,475	29,066	28,568
91 Plus, Still Accruing	38	33	37
Investment in loans and finance leases on non-accrual status	468	456	528
North America
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	12,526	11,186	10,271
Europe
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	3,581	3,871	3,539
Asia/Pacific
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	3,931	4,492	5,282
Mining
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	2,126	2,148	1,974
Latin America
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	4,141	4,269	4,319
Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	3,170	3,100	3,183
Customer
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	21,068	20,720	19,868
Customer | North America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	46	37	35
61-90 Days Past Due	8	12	8
91 Plus Days Past Due	27	24	52
Total Past Due	81	73	95
Current	7,291	6,507	5,889
Total gross finance receivables	7,372	6,580	5,984
91 Plus, Still Accruing	4	6	3
Investment in loans and finance leases on non-accrual status	27	26	59
Customer | Europe
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	16	26	23
61-90 Days Past Due	23	15	9
91 Plus Days Past Due	29	29	36
Total Past Due	68	70	68
Current	2,607	2,805	2,487
Total gross finance receivables	2,675	2,875	2,555
91 Plus, Still Accruing	6	8	9
Investment in loans and finance leases on non-accrual status	28	28	38
Customer | Asia/Pacific
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	29	55	53
61-90 Days Past Due	22	46	19
91 Plus Days Past Due	69	59	54
Total Past Due	120	160	126
Current	2,773	3,158	3,343
Total gross finance receivables	2,893	3,318	3,469
91 Plus, Still Accruing	16	11	18
Investment in loans and finance leases on non-accrual status	54	50	36
Customer | Mining
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	28	3	0
61-90 Days Past Due	0	0	1
91 Plus Days Past Due	11	12	12
Total Past Due	39	15	13
Current	2,084	2,128	1,960
Total gross finance receivables	2,123	2,143	1,973
91 Plus, Still Accruing	0	0	0
Investment in loans and finance leases on non-accrual status	62	23	12
Customer | Latin America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	55	54	62
61-90 Days Past Due	23	25	19
91 Plus Days Past Due	196	196	153
Total Past Due	274	275	234
Current	2,583	2,438	2,481
Total gross finance receivables	2,857	2,713	2,715
91 Plus, Still Accruing	8	5	0
Investment in loans and finance leases on non-accrual status	201	210	163
Customer | Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	1	55	15
61-90 Days Past Due	4	30	14
91 Plus Days Past Due	64	60	126
Total Past Due	69	145	155
Current	3,079	2,946	3,017
Total gross finance receivables	3,148	3,091	3,172
91 Plus, Still Accruing	1	0	4
Investment in loans and finance leases on non-accrual status	96	119	220
Dealer
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	5,169	5,254	5,586
Investment in loans and finance leases on non-accrual status	0	0	0
Dealer | North America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	0	0	0
Current	3,209	3,034	2,931
Total gross finance receivables	3,209	3,034	2,931
91 Plus, Still Accruing	0	0	0
Dealer | Europe
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	0	0	0
Current	467	569	652
Total gross finance receivables	467	569	652
91 Plus, Still Accruing	0	0	0
Dealer | Asia/Pacific
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	0	0	0
Current	637	706	945
Total gross finance receivables	637	706	945
91 Plus, Still Accruing	0	0	0
Dealer | Mining
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	0	0	0
Current	3	5	1
Total gross finance receivables	3	5	1
91 Plus, Still Accruing	0	0	0
Dealer | Latin America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	0	0	0
Current	853	940	1,057
Total gross finance receivables	853	940	1,057
91 Plus, Still Accruing	0	0	0
Dealer | Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	0	0	0
Current	0	0	0
Total gross finance receivables	0	0	0
91 Plus, Still Accruing	0	0	0
Caterpillar Purchased Receivables
Financing Receivable, Recorded Investment, Past Due
Total gross finance receivables	3,238	3,092	3,114
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	23	26	17
61-90 Days Past Due	5	5	3
91 Plus Days Past Due	1	2	2
Total Past Due	29	33	22
Current	1,916	1,539	1,334
Total gross finance receivables	1,945	1,572	1,356
91 Plus, Still Accruing	1	2	2
Caterpillar Purchased Receivables | Europe
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	4	2	1
61-90 Days Past Due	1	1	0
91 Plus Days Past Due	5	1	0
Total Past Due	10	4	1
Current	429	423	331
Total gross finance receivables	439	427	332
91 Plus, Still Accruing	1	0	0
Investment in loans and finance leases on non-accrual status	4
Caterpillar Purchased Receivables | Asia/Pacific
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	0	0	0
Current	401	468	868
Total gross finance receivables	401	468	868
91 Plus, Still Accruing	0	0	0
Caterpillar Purchased Receivables | Mining
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	0	0	0
Current	0	0	0
Total gross finance receivables	0	0	0
91 Plus, Still Accruing	0	0	0
Caterpillar Purchased Receivables | Latin America
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	6	0	0
61-90 Days Past Due	5	0	0
91 Plus Days Past Due	0	0	0
Total Past Due	11	0	0
Current	420	616	547
Total gross finance receivables	431	616	547
91 Plus, Still Accruing	0	0	0
Caterpillar Purchased Receivables | Caterpillar Power Finance
Financing Receivable, Recorded Investment, Past Due
31-60 Days Past Due	0	0	0
61-90 Days Past Due	0	0	0
91 Plus Days Past Due	1	1	1
Total Past Due	1	1	1
Current	21	8	10
Total gross finance receivables	22	9	11
91 Plus, Still Accruing	$ 1	$ 1	$ 1