Financing Receivables - By Portfolio Segment (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($)
Financing receivables
Amortized cost/Recorded investment	$ 20,072	$ 22,421
Allowance for credit losses:
Allowance for credit losses, beginning balance	221
Allowance for credit losses, ending balance	$ 238	221
Total Lease Receivable and Loan Receivable Portfolio Segments
Financing receivables
Number of portfolio segments | item	2
Number of classes of financing receivable | item	3
Amortized cost/Recorded investment	$ 17,741	18,590
Recorded investment collectively evaluated for impairment		18,399
Recorded investment individually evaluated for impairment		191
Allowance for credit losses:
Allowance for credit losses, beginning balance	210	279
Write-offs	(19)	(63)
Recoveries	1	2
Provision	9	(5)
Other	(16)	(2)
Allowance for credit losses, ending balance	226	210
Related allowance, collectively evaluated for impairment		39
Related allowance, individually evaluated for impairment		171
Total Lease Receivable and Loan Receivable Portfolio Segments | Americas
Financing receivables
Amortized cost/Recorded investment	9,760	10,144
Recorded investment collectively evaluated for impairment		10,032
Recorded investment individually evaluated for impairment		112
Allowance for credit losses:
Allowance for credit losses, beginning balance	120	158
Write-offs	(16)	(42)
Recoveries	0	1
Provision	3	5
Other	(13)	(1)
Allowance for credit losses, ending balance	117	120
Related allowance, collectively evaluated for impairment		25
Related allowance, individually evaluated for impairment		96
Total Lease Receivable and Loan Receivable Portfolio Segments | EMEA
Financing receivables
Amortized cost/Recorded investment	4,785	5,087
Recorded investment collectively evaluated for impairment		5,040
Recorded investment individually evaluated for impairment		47
Allowance for credit losses:
Allowance for credit losses, beginning balance	54	65
Write-offs	(1)	(3)
Recoveries		0
Provision	7	(7)
Other	(2)	0
Allowance for credit losses, ending balance	73	54
Related allowance, collectively evaluated for impairment		11
Related allowance, individually evaluated for impairment		43
Total Lease Receivable and Loan Receivable Portfolio Segments | Asia Pacific
Financing receivables
Amortized cost/Recorded investment	3,196	3,359
Recorded investment collectively evaluated for impairment		3,326
Recorded investment individually evaluated for impairment		32
Allowance for credit losses:
Allowance for credit losses, beginning balance	36	56
Write-offs	(2)	(18)
Recoveries	1	1
Provision	(1)	(3)
Other	(1)	(1)
Allowance for credit losses, ending balance	36	36
Related allowance, collectively evaluated for impairment		4
Related allowance, individually evaluated for impairment		32
Lease receivables
Financing receivables
Amortized cost/Recorded investment	5,654	5,567
Allowance for credit losses:
Allowance for credit losses, beginning balance	72	99
Write-offs		(16)
Provision		(6)
Allowance for credit losses, ending balance	79	72
Lease receivables | Americas
Financing receivables
Amortized cost/Recorded investment	3,609	3,419
Allowance for credit losses:
Allowance for credit losses, beginning balance	33	53
Allowance for credit losses, ending balance	41	33
Lease receivables | EMEA
Financing receivables
Amortized cost/Recorded investment	1,122	1,186
Allowance for credit losses:
Allowance for credit losses, beginning balance	23	22
Allowance for credit losses, ending balance	23	23
Lease receivables | Asia Pacific
Financing receivables
Amortized cost/Recorded investment	923	963
Allowance for credit losses:
Allowance for credit losses, beginning balance	16	24
Allowance for credit losses, ending balance	15	16
Loan receivables
Financing receivables
Amortized cost/Recorded investment	12,087	13,022
Allowance for credit losses:
Allowance for credit losses, beginning balance	138	179
Write-offs		(47)
Provision		2
Allowance for credit losses, ending balance	147	138
Loan receivables | Americas
Financing receivables
Amortized cost/Recorded investment	6,151	6,726
Allowance for credit losses:
Allowance for credit losses, beginning balance	88	105
Allowance for credit losses, ending balance	75	88
Loan receivables | EMEA
Financing receivables
Amortized cost/Recorded investment	3,663	3,901
Allowance for credit losses:
Allowance for credit losses, beginning balance	31	43
Allowance for credit losses, ending balance	50	31
Loan receivables | Asia Pacific
Financing receivables
Amortized cost/Recorded investment	2,273	2,395
Allowance for credit losses:
Allowance for credit losses, beginning balance	20	32
Allowance for credit losses, ending balance	22	20
Accounting Standards Update 2016-13 | Adjustment
Allowance for credit losses:
Allowance for credit losses, beginning balance	41
Allowance for credit losses, ending balance		41
Accounting Standards Update 2016-13 | Adjustment | Americas
Allowance for credit losses:
Allowance for credit losses, beginning balance	21
Allowance for credit losses, ending balance		21
Accounting Standards Update 2016-13 | Adjustment | EMEA
Allowance for credit losses:
Allowance for credit losses, beginning balance	15
Allowance for credit losses, ending balance		15
Accounting Standards Update 2016-13 | Adjustment | Asia Pacific
Allowance for credit losses:
Allowance for credit losses, beginning balance	5
Allowance for credit losses, ending balance		5
Accounting Standards Update 2016-13 | Adjustment | Total Lease Receivable and Loan Receivable Portfolio Segments
Allowance for credit losses:
Allowance for credit losses, beginning balance	252
Allowance for credit losses, ending balance		252
Accounting Standards Update 2016-13 | Adjustment | Total Lease Receivable and Loan Receivable Portfolio Segments | Americas
Allowance for credit losses:
Allowance for credit losses, beginning balance	142
Allowance for credit losses, ending balance		142
Accounting Standards Update 2016-13 | Adjustment | Total Lease Receivable and Loan Receivable Portfolio Segments | EMEA
Allowance for credit losses:
Allowance for credit losses, beginning balance	69
Allowance for credit losses, ending balance		69
Accounting Standards Update 2016-13 | Adjustment | Total Lease Receivable and Loan Receivable Portfolio Segments | Asia Pacific
Allowance for credit losses:
Allowance for credit losses, beginning balance	41
Allowance for credit losses, ending balance		41
Accounting Standards Update 2016-13 | Adjustment | Lease receivables
Allowance for credit losses:
Allowance for credit losses, beginning balance	89
Allowance for credit losses, ending balance		89
Accounting Standards Update 2016-13 | Adjustment | Lease receivables | Americas
Allowance for credit losses:
Allowance for credit losses, beginning balance	44
Allowance for credit losses, ending balance		44
Accounting Standards Update 2016-13 | Adjustment | Lease receivables | EMEA
Allowance for credit losses:
Allowance for credit losses, beginning balance	27
Allowance for credit losses, ending balance		27
Accounting Standards Update 2016-13 | Adjustment | Lease receivables | Asia Pacific
Allowance for credit losses:
Allowance for credit losses, beginning balance	18
Allowance for credit losses, ending balance		18
Accounting Standards Update 2016-13 | Adjustment | Loan receivables
Allowance for credit losses:
Allowance for credit losses, beginning balance	163
Allowance for credit losses, ending balance		163
Accounting Standards Update 2016-13 | Adjustment | Loan receivables | Americas
Allowance for credit losses:
Allowance for credit losses, beginning balance	98
Allowance for credit losses, ending balance		98
Accounting Standards Update 2016-13 | Adjustment | Loan receivables | EMEA
Allowance for credit losses:
Allowance for credit losses, beginning balance	42
Allowance for credit losses, ending balance		42
Accounting Standards Update 2016-13 | Adjustment | Loan receivables | Asia Pacific
Allowance for credit losses:
Allowance for credit losses, beginning balance	$ 22
Allowance for credit losses, ending balance		$ 22