Financing Receivables - By Portfolio Segment (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2017 USD ($) item	Dec. 31, 2016 USD ($)
Financing receivables
Financing receivables pledged as collateral for borrowings	$ 737	$ 689
Financing receivables held for sale	$ 0	0
Total Lease Receivable and Loan Receivable Portfolio Segments
Financing receivables
Number of portfolio segments | item	2
Number of classes of financing receivable | item	3
Financing receivables on a gross basis	$ 17,401	18,073
Collectively evaluated for impairment	17,097	17,726
Individually evaluated for impairment	304	347
Allowance for credit losses:
Allowance for credit losses, beginning balance	410	590
Write-offs	(70)	(237)
Recoveries	0	2
Provision	17	58
Other	10	(3)
Allowance for credit losses, ending balance	368	410
Collectively evaluated for impairment	91	90
Individually evaluated for impairment	277	320
Total Lease Receivable and Loan Receivable Portfolio Segments | Americas
Financing receivables
Financing receivables on a gross basis	9,456	10,015
Collectively evaluated for impairment	9,284	9,847
Individually evaluated for impairment	173	168
Allowance for credit losses:
Allowance for credit losses, beginning balance	223	175
Write-offs	(11)	(36)
Recoveries	0	2
Provision	13	65
Other	(1)	17
Allowance for credit losses, ending balance	224	223
Collectively evaluated for impairment	62	62
Individually evaluated for impairment	162	161
Total Lease Receivable and Loan Receivable Portfolio Segments | EMEA
Financing receivables
Financing receivables on a gross basis	4,303	4,480
Collectively evaluated for impairment	4,272	4,460
Individually evaluated for impairment	31	20
Allowance for credit losses:
Allowance for credit losses, beginning balance	22	72
Write-offs	0	(48)
Recoveries	0	0
Provision	9	(1)
Other	4	(1)
Allowance for credit losses, ending balance	35	22
Collectively evaluated for impairment	14	13
Individually evaluated for impairment	21	9
Total Lease Receivable and Loan Receivable Portfolio Segments | Asia Pacific
Financing receivables
Financing receivables on a gross basis	3,642	3,578
Collectively evaluated for impairment	3,541	3,419
Individually evaluated for impairment	100	159
Allowance for credit losses:
Allowance for credit losses, beginning balance	165	343
Write-offs	(59)	(154)
Recoveries	0	0
Provision	(4)	(6)
Other	7	(18)
Allowance for credit losses, ending balance	109	165
Collectively evaluated for impairment	15	15
Individually evaluated for impairment	94	150
Lease receivables
Financing receivables
Financing receivables on a gross basis	5,946	6,336
Allowance for credit losses:
Allowance for credit losses, beginning balance	133	213
Allowance for credit losses, ending balance	121	133
Lease receivables | Americas
Financing receivables
Financing receivables on a gross basis	3,442	3,830
Allowance for credit losses:
Allowance for credit losses, beginning balance	54	52
Allowance for credit losses, ending balance	69	54
Lease receivables | EMEA
Financing receivables
Financing receivables on a gross basis	1,202	1,171
Allowance for credit losses:
Allowance for credit losses, beginning balance	4	17
Allowance for credit losses, ending balance	4	4
Lease receivables | Asia Pacific
Financing receivables
Financing receivables on a gross basis	1,302	1,335
Allowance for credit losses:
Allowance for credit losses, beginning balance	76	143
Allowance for credit losses, ending balance	48	76
Loan receivables
Financing receivables
Financing receivables on a gross basis	11,455	11,737
Allowance for credit losses:
Allowance for credit losses, beginning balance	276	377
Allowance for credit losses, ending balance	246	276
Loan receivables | Americas
Financing receivables
Financing receivables on a gross basis	6,014	6,185
Allowance for credit losses:
Allowance for credit losses, beginning balance	169	122
Allowance for credit losses, ending balance	154	169
Loan receivables | EMEA
Financing receivables
Financing receivables on a gross basis	3,101	3,309
Allowance for credit losses:
Allowance for credit losses, beginning balance	18	55
Allowance for credit losses, ending balance	31	18
Loan receivables | Asia Pacific
Financing receivables
Financing receivables on a gross basis	2,340	2,243
Allowance for credit losses:
Allowance for credit losses, beginning balance	89	200
Allowance for credit losses, ending balance	$ 61	$ 89