Cat Financial Financing Activities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Receivables [Abstract]
Period after which collection of future income is considered as not probable (in days)	120 days
Customer
Impaired loans and finance leases
Recorded Investment	$ 736		$ 682
Unpaid Principal Balance	723		670
Related Allowance	101		73
Average Recorded Investment	714	573
Interest Income Recognized	4	3
Customer | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	367		378
Unpaid Principal Balance	365		377
Related Allowance	0		0
Average Recorded Investment	371	315
Interest Income Recognized	1	2
Customer | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	369		304
Unpaid Principal Balance	358		293
Related Allowance	101		73
Average Recorded Investment	343	258
Interest Income Recognized	3	1
Customer | North America
Impaired loans and finance leases
Recorded Investment	64		75
Unpaid Principal Balance	59		70
Related Allowance	12		10
Average Recorded Investment	70	139
Interest Income Recognized	1	1
Customer | North America | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	25		28
Unpaid Principal Balance	23		27
Related Allowance	0		0
Average Recorded Investment	28	67
Interest Income Recognized	1	1
Customer | North America | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	39		47
Unpaid Principal Balance	36		43
Related Allowance	12		10
Average Recorded Investment	42	72
Interest Income Recognized	0	0
Customer | Europe
Impaired loans and finance leases
Recorded Investment	81		85
Unpaid Principal Balance	78		82
Related Allowance	11		14
Average Recorded Investment	86	86
Interest Income Recognized	1	0
Customer | Europe | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	44		45
Unpaid Principal Balance	44		45
Related Allowance	0		0
Average Recorded Investment	45	46
Interest Income Recognized	0	0
Customer | Europe | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	37		40
Unpaid Principal Balance	34		37
Related Allowance	11		14
Average Recorded Investment	41	40
Interest Income Recognized	1	0
Customer | Asia Pacific
Impaired loans and finance leases
Recorded Investment	53		37
Unpaid Principal Balance	53		37
Related Allowance	11		8
Average Recorded Investment	47	23
Interest Income Recognized	1	1
Customer | Asia Pacific | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	5		2
Unpaid Principal Balance	5		2
Related Allowance	0		0
Average Recorded Investment	4	3
Interest Income Recognized	0	0
Customer | Asia Pacific | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	48		35
Unpaid Principal Balance	48		35
Related Allowance	11		8
Average Recorded Investment	43	20
Interest Income Recognized	1	1
Customer | Mining
Impaired loans and finance leases
Recorded Investment	40		24
Unpaid Principal Balance	39		24
Related Allowance	9		5
Average Recorded Investment	32	21
Interest Income Recognized	0	0
Customer | Mining | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	0		1
Unpaid Principal Balance	0		1
Related Allowance	0		0
Average Recorded Investment	0	8
Interest Income Recognized	0	0
Customer | Mining | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	40		23
Unpaid Principal Balance	39		23
Related Allowance	9		5
Average Recorded Investment	32	13
Interest Income Recognized	0	0
Customer | Latin America
Impaired loans and finance leases
Recorded Investment	68		50
Unpaid Principal Balance	68		50
Related Allowance	18		12
Average Recorded Investment	63	32
Interest Income Recognized	1	0
Customer | Latin America | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	8		7
Unpaid Principal Balance	8		7
Related Allowance	0		0
Average Recorded Investment	9	6
Interest Income Recognized	0	0
Customer | Latin America | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	60		43
Unpaid Principal Balance	60		43
Related Allowance	18		12
Average Recorded Investment	54	26
Interest Income Recognized	1	0
Customer | Caterpillar Power Finance
Impaired loans and finance leases
Recorded Investment	430		411
Unpaid Principal Balance	426		407
Related Allowance	40		24
Average Recorded Investment	416	272
Interest Income Recognized	0	1
Customer | Caterpillar Power Finance | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	285		295
Unpaid Principal Balance	285		295
Related Allowance	0		0
Average Recorded Investment	285	185
Interest Income Recognized	0	1
Customer | Caterpillar Power Finance | Impaired Loans and Finance Leases With An Allowance Recorded
Impaired loans and finance leases
Recorded Investment	145		116
Unpaid Principal Balance	141		112
Related Allowance	40		24
Average Recorded Investment	131	87
Interest Income Recognized	0	0
Dealer
Impaired loans and finance leases
Recorded Investment	0		0
Average Recorded Investment	$ 0	$ 0