Inventories - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019
Inventory, Net [Abstract]
Inventory valuation reserves	$ 430	$ 429
Inventory, Net, Items Net of Reserve Alternative [Abstract]
Finished goods	2,575	2,546
Work in process and raw materials	2,045	2,062
Total inventories, net	4,620	$ 4,608
Inventory Impairment	$ 105