Financing Activities (Details 3) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses
Allowance for credit losses	$ 401	$ 387	$ 348	$ 401
Allowance for credit losses as a percent of net finance receivables			1.26%	1.36%
Increase (decrease) in Allowance for credit losses	(53)
Financing Receivable, Allowance for Credit Losses
Balance at beginning of year	401	387
Receivables written off	(151)	(146)
Recoveries on receivables previously written off	32	47
Provision for credit losses	88	136
Adjustment due to sale of receivables	(1)	(3)
Foreign currency translation adjustment	(21)	(20)
Balance at end of period	348	401
Allowance for Credit Losses
Individually evaluated for impairment			$ 82	$ 75
Collectively evaluated for impairment			266	326
Allowance, Ending Balance	401	387	348	401
Recorded Investment in Finance Receivables
Individually evaluated for impairment			565	614
Collectively evaluated for impairment			27,026	28,861
Recorded Investment in Finance Receivables, Ending Balance			27,591	29,475
Customer
Financing Receivable, Allowance for Credit Losses
Allowance for credit losses	388	374	336	388
Financing Receivable, Allowance for Credit Losses
Balance at beginning of year	388	374
Receivables written off	(151)	(146)
Recoveries on receivables previously written off	32	47
Provision for credit losses	89	136
Adjustment due to sale of receivables	(1)	(3)
Foreign currency translation adjustment	(21)	(20)
Balance at end of period	336	388
Allowance for Credit Losses
Individually evaluated for impairment			82	75
Collectively evaluated for impairment			254	313
Allowance, Ending Balance	388	374	336	388
Recorded Investment in Finance Receivables
Individually evaluated for impairment			565	614
Collectively evaluated for impairment			19,243	20,454
Recorded Investment in Finance Receivables, Ending Balance			19,808	21,068
Dealer
Financing Receivable, Allowance for Credit Losses
Allowance for credit losses	10	10	9	10
Financing Receivable, Allowance for Credit Losses
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
Adjustment due to sale of receivables	0	0
Foreign currency translation adjustment	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
Allowance, Ending Balance	10	10	9	10
Recorded Investment in Finance Receivables
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			5,246	5,169
Recorded Investment in Finance Receivables, Ending Balance			5,246	5,169
Caterpillar Purchased Receivables
Financing Receivable, Allowance for Credit Losses
Allowance for credit losses	3	3	3	3
Financing Receivable, Allowance for Credit Losses
Balance at beginning of year	3	3
Receivables written off	0	0
Recoveries on receivables previously written off	0	0
Provision for credit losses	0	0
Adjustment due to sale of receivables	0	0
Foreign currency translation adjustment	0	0
Balance at end of period	3	3
Allowance for Credit Losses
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			3	3
Allowance, Ending Balance	$ 3	$ 3	3	3
Recorded Investment in Finance Receivables
Individually evaluated for impairment			0	0
Collectively evaluated for impairment			2,537	3,238
Recorded Investment in Finance Receivables, Ending Balance			$ 2,537	$ 3,238