Financing Receivables - By Portfolio Segment (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017 USD ($) item	Dec. 31, 2016 USD ($)
Financing receivables
Financing receivables pledged as collateral for borrowings	$ 658	$ 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	$ 17,179	18,073
Collectively evaluated for impairment	16,811	17,726
Individually evaluated for impairment	368	347
Allowance for credit losses:
Allowance for credit losses, beginning balance	410	590
Write-offs	(9)	(237)
Recoveries	0	2
Provision	12	58
Other	11	(3)
Allowance for credit losses, ending balance	424	410
Collectively evaluated for impairment	80	90
Individually evaluated for impairment	344	320
Total Lease Receivable and Loan Receivable Portfolio Segments | Americas
Financing receivables
Financing receivables on a gross basis	9,428	10,015
Collectively evaluated for impairment	9,250	9,847
Individually evaluated for impairment	179	168
Allowance for credit losses:
Allowance for credit losses, beginning balance	223	175
Write-offs	(9)	(36)
Recoveries	0	2
Provision	6	65
Other	2	17
Allowance for credit losses, ending balance	223	223
Collectively evaluated for impairment	54	62
Individually evaluated for impairment	169	161
Total Lease Receivable and Loan Receivable Portfolio Segments | EMEA
Financing receivables
Financing receivables on a gross basis	4,216	4,480
Collectively evaluated for impairment	4,190	4,460
Individually evaluated for impairment	26	20
Allowance for credit losses:
Allowance for credit losses, beginning balance	22	72
Write-offs	0	(48)
Recoveries	0	0
Provision	7	(1)
Other	1	(1)
Allowance for credit losses, ending balance	29	22
Collectively evaluated for impairment	11	13
Individually evaluated for impairment	18	9
Total Lease Receivable and Loan Receivable Portfolio Segments | Asia Pacific
Financing receivables
Financing receivables on a gross basis	3,535	3,578
Collectively evaluated for impairment	3,371	3,419
Individually evaluated for impairment	164	159
Allowance for credit losses:
Allowance for credit losses, beginning balance	165	343
Write-offs	0	(154)
Recoveries	0	0
Provision	(1)	(6)
Other	8	(18)
Allowance for credit losses, ending balance	172	165
Collectively evaluated for impairment	14	15
Individually evaluated for impairment	157	150
Lease receivables
Financing receivables
Financing receivables on a gross basis	6,098	6,336
Allowance for credit losses:
Allowance for credit losses, beginning balance	133	213
Allowance for credit losses, ending balance	140	133
Lease receivables | Americas
Financing receivables
Financing receivables on a gross basis	3,602	3,830
Allowance for credit losses:
Allowance for credit losses, beginning balance	54	52
Allowance for credit losses, ending balance	61	54
Lease receivables | EMEA
Financing receivables
Financing receivables on a gross basis	1,154	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	1,342	1,335
Allowance for credit losses:
Allowance for credit losses, beginning balance	76	143
Allowance for credit losses, ending balance	75	76
Loan receivables
Financing receivables
Financing receivables on a gross basis	11,081	11,737
Allowance for credit losses:
Allowance for credit losses, beginning balance	276	377
Allowance for credit losses, ending balance	285	276
Loan receivables | Americas
Financing receivables
Financing receivables on a gross basis	5,826	6,185
Allowance for credit losses:
Allowance for credit losses, beginning balance	169	122
Allowance for credit losses, ending balance	162	169
Loan receivables | EMEA
Financing receivables
Financing receivables on a gross basis	3,062	3,309
Allowance for credit losses:
Allowance for credit losses, beginning balance	18	55
Allowance for credit losses, ending balance	26	18
Loan receivables | Asia Pacific
Financing receivables
Financing receivables on a gross basis	2,193	2,243
Allowance for credit losses:
Allowance for credit losses, beginning balance	89	200
Allowance for credit losses, ending balance	$ 97	$ 89