Cat Financial Financing Activities (Details 2) (USD $) In Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2010
Allowance for credit loss activity:
Balance at beginning of year	$ 362	$ 376
Provision for credit losses	120	205
Receivables written off	(159)	(288)
Recoveries on receivables previously written off	39	51
Adjustment due to sale of receivables	(1)
Foreign currency translation adjustment	(2)
Adjustment to adopt consolidation of variable-interest entities		18
Balance at end of year	359	362
Customer
Allowance for credit loss activity:
Balance at beginning of year	357
Provision for credit losses	119
Receivables written off	(159)
Recoveries on receivables previously written off	39
Adjustment due to sale of receivables	(1)
Foreign currency translation adjustment	(2)
Balance at end of year	353
Dealer
Allowance for credit loss activity:
Balance at beginning of year	5
Provision for credit losses	1
Balance at end of year	$ 6