Basis of Presentation - Change in Presentation (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Sales and services	[1],[2]	$ 2,200	$ 2,352	$ 6,695	$ 7,297
Sales
Sales and services	[1],[3]	804	856	2,379	2,628
Cost of sales and services	[3]	515	539	1,531	1,664
Services, maintenance and rentals
Sales and services	[3]	1,336	1,431	4,132	4,465
Cost of sales and services	[3]	$ 772	838	$ 2,400	2,620
As Reported | Sales
Sales and services			943		2,893
Cost of sales and services			570		1,755
As Reported | Services, maintenance and rentals
Sales and services			1,344		4,200
Cost of sales and services			807		2,529
Change | Sales
Sales and services			(87)		(265)
Cost of sales and services			(31)		(91)
Change | Services, maintenance and rentals
Sales and services			87		265
Cost of sales and services			$ 31		$ 91

[1] 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.

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

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