Adoption of New Leasing Standard - Lessor - Components of Lease Income (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Lessor, Lease, Description [Line Items]
Economic life of leased product				5 years
Lease income - sales type		$ 200	$ 175	$ 484	$ 507
Interest income on lease receivables		60	65	184	204
Lease income - operating leases	[1]	99	109	303	331
Variable lease income		25	28	80	89
Total Lease income		384	377	1,051	1,131
Total Revenues	[2],[3]	2,200	2,352	6,695	7,297
Profit at lease commencement, sales type leases		86		206
Profit at lease commencement, sales type leases			76		221
Services
Lessor, Lease, Description [Line Items]
Total Revenues	[4]	$ 1,336	$ 1,431	4,132	4,465
Services | ASU 2016-02
Lessor, Lease, Description [Line Items]
Total Revenues				$ 30	$ 28

[1] Operating lease income for the nine months ended September 30, 2019 and 2018 exclude service revenues of $30 and $28, respectively, which were reported in operating lease income for the three months ended March 31, 2019 and 2018

[2] Certain prior year amounts have been revised to conform to the current year presentation. Refer to Note 1 - Basis of Presentation - Change in Presentation, for additional information.

[3] Geographic area data is based upon the location of the subsidiary reporting the revenue.

[4] Certain prior year amounts have been conformed to the current year presentation. Refer to Note 1 - Basis of Presentation for additional information.