Cat Financial Financing Activities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 D	Mar. 31, 2011	Dec. 31, 2011
Cat Financial Financing Activities
Period after which collection of future income is considered as not probable (in days)	120
Impaired loans and finance leases
Recorded Investment	$ 589		$ 575
Unpaid Principal Balance	575		557
Related Allowance	54		56
Average recorded investment	573	696
Interest Income Recognized	3	6
Period after which unpaid contractual payments are considered as past due (in days)	30
Investment in loans/finance leases on nonaccrual status	523		472
Past due loans and finance leases
31-60	226		194
61-90	156		104
91+	488		442
Total Past Due	870		740
Current	19,865		19,240
Total Finance Receivables	20,735		19,980
91+ Still Accruing	62		58
Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	331		326
Unpaid Principal Balance	325		317
Average recorded investment	315	319
Interest Income Recognized	2	2
Impaired Loans and Finance Leases with an Allowance Recorded
Impaired loans and finance leases
Recorded Investment	258		249
Unpaid Principal Balance	250		240
Related Allowance	54		56
Average recorded investment	258	377
Interest Income Recognized	1	4
North America
Past due loans and finance leases
Total Finance Receivables	7,257		7,291
Europe
Past due loans and finance leases
Total Finance Receivables	2,363		2,281
Asia Pacific
Past due loans and finance leases
Total Finance Receivables	3,076		3,038
Latin America
Past due loans and finance leases
Total Finance Receivables	3,236		2,965
Global Power Finance
Past due loans and finance leases
Total Finance Receivables	3,130		2,920
Customer
Past due loans and finance leases
Total Finance Receivables	18,208		17,593
Customer | North America
Impaired loans and finance leases
Recorded Investment	128		152
Unpaid Principal Balance	122		144
Related Allowance	15		15
Average recorded investment	139	275
Interest Income Recognized	1	3
Investment in loans/finance leases on nonaccrual status	103		112
Past due loans and finance leases
31-60	49		74
61-90	19		39
91+	106		111
Total Past Due	174		224
Current	5,374		5,378
Total Finance Receivables	5,548		5,602
91+ Still Accruing	12		9
Customer | North America | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	56		83
Unpaid Principal Balance	55		80
Average recorded investment	67	84
Interest Income Recognized	1	1
Customer | North America | Impaired Loans and Finance Leases with an Allowance Recorded
Impaired loans and finance leases
Recorded Investment	72		69
Unpaid Principal Balance	67		64
Related Allowance	15		15
Average recorded investment	72	191
Interest Income Recognized		2
Customer | Europe
Impaired loans and finance leases
Recorded Investment	89		83
Unpaid Principal Balance	86		79
Related Allowance	12		12
Average recorded investment	86	71
Interest Income Recognized		1
Investment in loans/finance leases on nonaccrual status	56		58
Past due loans and finance leases
31-60	36		27
61-90	25		11
91+	61		57
Total Past Due	122		95
Current	2,185		2,129
Total Finance Receivables	2,307		2,224
91+ Still Accruing	13		10
Customer | Europe | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	45		47
Unpaid Principal Balance	44		46
Average recorded investment	46	7
Customer | Europe | Impaired Loans and Finance Leases with an Allowance Recorded
Impaired loans and finance leases
Recorded Investment	44		36
Unpaid Principal Balance	42		33
Related Allowance	12		12
Average recorded investment	40	64
Interest Income Recognized		1
Customer | Asia Pacific
Impaired loans and finance leases
Recorded Investment	28		17
Unpaid Principal Balance	28		17
Related Allowance	5		3
Average recorded investment	23	32
Interest Income Recognized	1
Investment in loans/finance leases on nonaccrual status	33		24
Past due loans and finance leases
31-60	55		47
61-90	33		23
91+	57		38
Total Past Due	145		108
Current	2,751		2,769
Total Finance Receivables	2,896		2,877
91+ Still Accruing	24		14
Customer | Asia Pacific | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	4		4
Unpaid Principal Balance	4		4
Average recorded investment	3	5
Customer | Asia Pacific | Impaired Loans and Finance Leases with an Allowance Recorded
Impaired loans and finance leases
Recorded Investment	24		13
Unpaid Principal Balance	24		13
Related Allowance	5		3
Average recorded investment	20	27
Interest Income Recognized	1
Customer | Mining
Impaired loans and finance leases
Recorded Investment	21		21
Unpaid Principal Balance	21		21
Related Allowance	4		4
Average recorded investment	21	8
Investment in loans/finance leases on nonaccrual status	12		12
Past due loans and finance leases
91+	12		12
Total Past Due	12		12
Current	1,660		1,473
Total Finance Receivables	1,672		1,485
Customer | Mining | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	8		8
Unpaid Principal Balance	8		8
Average recorded investment	8	8
Customer | Mining | Impaired Loans and Finance Leases with an Allowance Recorded
Impaired loans and finance leases
Recorded Investment	13		13
Unpaid Principal Balance	13		13
Related Allowance	4		4
Average recorded investment	13
Customer | Latin America
Impaired loans and finance leases
Recorded Investment	30		34
Unpaid Principal Balance	30		34
Related Allowance	6		6
Average recorded investment	32	51
Interest Income Recognized		1
Investment in loans/finance leases on nonaccrual status	162		108
Past due loans and finance leases
31-60	43		32
61-90	24		15
91+	147		99
Total Past Due	214		146
Current	2,441		2,339
Total Finance Receivables	2,655		2,485
Customer | Latin America | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	4		9
Unpaid Principal Balance	4		9
Average recorded investment	6	4
Customer | Latin America | Impaired Loans and Finance Leases with an Allowance Recorded
Impaired loans and finance leases
Recorded Investment	26		25
Unpaid Principal Balance	26		25
Related Allowance	6		6
Average recorded investment	26	47
Interest Income Recognized		1
Customer | Global Power Finance
Impaired loans and finance leases
Recorded Investment	293		268
Unpaid Principal Balance	288		262
Related Allowance	12		16
Average recorded investment	272	259
Interest Income Recognized	1	1
Investment in loans/finance leases on nonaccrual status	157		158
Past due loans and finance leases
31-60	43		14
61-90	55		16
91+	105		125
Total Past Due	203		155
Current	2,927		2,765
Total Finance Receivables	3,130		2,920
91+ Still Accruing	13		25
Customer | Global Power Finance | Impaired Loans and Finance Leases with No Allowance Recorded
Impaired loans and finance leases
Recorded Investment	214		175
Unpaid Principal Balance	210		170
Average recorded investment	185	211
Interest Income Recognized	1	1
Customer | Global Power Finance | Impaired Loans and Finance Leases with an Allowance Recorded
Impaired loans and finance leases
Recorded Investment	79		93
Unpaid Principal Balance	78		92
Related Allowance	12		16
Average recorded investment	87	48
Dealer
Past due loans and finance leases
Total Finance Receivables	2,527		2,387
Dealer | North America
Past due loans and finance leases
Current	1,709		1,689
Total Finance Receivables	1,709		1,689
Dealer | Europe
Past due loans and finance leases
Current	56		57
Total Finance Receivables	56		57
Dealer | Asia Pacific
Past due loans and finance leases
Current	180		161
Total Finance Receivables	180		161
Dealer | Mining
Past due loans and finance leases
Current	1
Total Finance Receivables	1
Dealer | Latin America
Past due loans and finance leases
Current	581		480
Total Finance Receivables	$ 581		$ 480