Inventories - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018
Schedule of Inventory [Line Items]
Inventory write-down		$ 572
Inventory Reserve for Excess Raw Materials [Member]
Schedule of Inventory [Line Items]
Inventory write-down	$ 410	$ 440