Cat Financial Financing Activities (Details 3) - Finance Receivables - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Allowance for credit loss activity:
Balance at beginning of year	$ 362	$ 341
Receivables written off	(235)	(157)
Recoveries on receivables previously written off	46	43
Provision for credit losses	349	128
Other	(15)	7
Balance at end of year	507	362
Allowance for Credit Losses:
Individually evaluated for impairment			$ 302	$ 149
Collectively evaluated for impairment			205	213
Ending Balance	362	341	507	362
Recorded Investment in Finance Receivables:
Individually evaluated for impairment			936	942
Collectively evaluated for impairment			21,490	21,690
Ending balance-recorded investment in finance receivables			22,426	22,632
Customer
Allowance for credit loss activity:
Balance at beginning of year	353	331
Receivables written off	(235)	(157)
Recoveries on receivables previously written off	46	43
Provision for credit losses	337	129
Other	(15)	7
Balance at end of year	486	353
Allowance for Credit Losses:
Individually evaluated for impairment			288	149
Collectively evaluated for impairment			198	204
Ending Balance	353	331	486	353
Recorded Investment in Finance Receivables:
Individually evaluated for impairment			858	942
Collectively evaluated for impairment			18,152	18,226
Ending balance-recorded investment in finance receivables			19,010	19,168
Dealer
Allowance for credit loss activity:
Balance at beginning of year	9	10
Receivables written off	0	0
Recoveries on receivables previously written off	0	0
Provision for credit losses	12	(1)
Other	0	0
Balance at end of year	21	9
Allowance for Credit Losses:
Individually evaluated for impairment			14	0
Collectively evaluated for impairment			7	9
Ending Balance	$ 9	$ 10	21	9
Recorded Investment in Finance Receivables:
Individually evaluated for impairment			78	0
Collectively evaluated for impairment			3,338	3,464
Ending balance-recorded investment in finance receivables			$ 3,416	$ 3,464