Cat Financial Financing Activities (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Allowance for Credit Loss Activity
Balance at beginning of year	$ 398	$ 375
Receivables written off	(23)	(151)
Recoveries on receivables previously written off	11	47
Provision for credit losses	17	150
Other	(14)	(23)
Balance at end of period	389	398
Allowance for Credit Losses
Individually evaluated for impairment	74	75
Collectively evaluated for impairment	315	323
Ending Balance	389	398
Recorded Investment in Finance Receivables
Individually evaluated for impairment	663	613
Collectively evaluated for impairment	22,459	23,453
Ending balance-recorded investment in finance receivables	23,122	24,066
Customer
Allowance for Credit Loss Activity
Balance at beginning of year	388	365
Receivables written off	(23)	(151)
Recoveries on receivables previously written off	11	47
Provision for credit losses	18	150
Other	(14)	(23)
Balance at end of period	380	388
Allowance for Credit Losses
Individually evaluated for impairment	74	75
Collectively evaluated for impairment	306	313
Ending Balance	380	388
Recorded Investment in Finance Receivables
Individually evaluated for impairment	663	613
Collectively evaluated for impairment	18,921	19,899
Ending balance-recorded investment in finance receivables	19,584	20,512
Dealer
Allowance for Credit Loss Activity
Balance at beginning of year	10	10
Receivables written off	0	0
Recoveries on receivables previously written off	0	0
Provision for credit losses	(1)	0
Other	0	0
Balance at end of period	9	10
Allowance for Credit Losses
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	9	10
Ending Balance	9	10
Recorded Investment in Finance Receivables
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	3,538	3,554
Ending balance-recorded investment in finance receivables	$ 3,538	$ 3,554