Allowance for Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Allowance for credit losses, finance receivables
Beginning balance	$ 522	$ 449	$ 484	$ 373
Charge-offs	(132)	(113)	(369)	(311)
Recoveries	40	30	113	93
Provision for credit losses	140	113	334	324
Other	5	(1)	13	(1)
Ending balance	575	478	575	478
Analysis of ending balance of allowance for credit losses, finance receivables
Collective impairment allowance	554	457	554	457
Specific impairment allowance	21	21	21	21
Ending balance	575	478	575	478
Analysis of ending balance of finance receivables
Collectively evaluated for impairment	110,633	100,863	110,633	100,863
Specifically evaluated for impairment	539	506	539	506
Financing Receivables	111,172	101,369	111,172	101,369	$ 103,465
Ending balance, net of allowance for credit losses	110,597	100,891	110,597	100,891
Allowance for credit losses, net investment in operating leases
Beginning balance	66	63	64	49
Charge-offs	(51)	(44)	(155)	(125)
Recoveries	25	20	73	60
Other	0	(1)	1	0
Ending balance	69	63	69	63
Analysis of Ending Balance of Allowance for Credit Losses, Net Investment in Operating Leases [Abstract]
Collective impairment allowance	69	63	69	63
Specific impairment allowance	0	0	0	0
Ending balance	69	63	69	63
Analysis of ending balance of net investment in operating leases
Collectively evaluated for impairment	27,000	27,024	27,000	27,024
Individually evaluated for impairment	0	0	0	0
Net investment in operating leases before allowance for credit losses	27,000	27,024	27,000	27,024	27,273
Ending balance, net investment in operating leases	26,931	26,961	26,931	26,961
Total allowance
Beginning balance	588	512	548	422
Charge-offs	(183)	(157)	(524)	(436)
Recoveries	65	50	186	153
Provision for credit losses	169	138	420	403
Other	5	(2)	14	(1)
Ending balance	644	541	644	541
Analysis of Ending Balance of Finance Receivables and Net Investment in Operating Leases [Abstract]
Collective impairment allowance	623	520	623	520
Specific impairment allowance	21	21	21	21
Ending balance	644	541	644	541
Net Investment in Operating Leases [Member]
Allowance for credit losses, finance receivables
Provision for credit losses	29	25	86	79
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	28		28		21
Allowance for credit losses, finance receivables
Beginning balance	507	432	469	357
Charge-offs	(132)	(108)	(366)	(304)
Recoveries	36	29	105	89
Provision for credit losses	146	112	341	323
Other	5	(1)	13	(1)
Ending balance	562	464	562	464
Analysis of ending balance of allowance for credit losses, finance receivables
Collective impairment allowance	541	445	541	445
Specific impairment allowance	21	19	21	19
Ending balance	562	464	562	464
Analysis of ending balance of finance receivables
Collectively evaluated for impairment	72,069	64,743	72,069	64,743
Specifically evaluated for impairment	387	366	387	366
Financing Receivables	72,456	65,109	72,456	65,109	65,338
Ending balance, net of allowance for credit losses	71,894	64,645	71,894	64,645
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	1		1		0
Allowance for credit losses, finance receivables
Beginning balance	15	17	15	16
Charge-offs	0	(5)	(3)	(7)
Recoveries	4	1	8	4
Provision for credit losses	(6)	1	(7)	1
Other	0	0	0	0
Ending balance	13	14	13	14
Analysis of ending balance of allowance for credit losses, finance receivables
Collective impairment allowance	13	12	13	12
Specific impairment allowance	0	2	0	2
Ending balance	13	14	13	14
Analysis of ending balance of finance receivables
Collectively evaluated for impairment	38,564	36,120	38,564	36,120
Specifically evaluated for impairment	152	140	152	140
Financing Receivables	38,716	36,260	38,716	36,260	$ 38,127
Ending balance, net of allowance for credit losses	$ 38,703	$ 36,246	$ 38,703	$ 36,246