Basis of Presentation (Unaudited) (Details 3) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Change in Contract with Customer, Asset and Liability [Abstract]
Unbilled receivables, net	$ 5,600		$ 5,600		$ 3,465
Amount of increase (decrease) in Unbilled Receivables			$ 2,135
Percent increase (decrease) in Unbilled Receivables			62.00%
Advance payments and amounts in excess of costs incurred	(1,686)		$ (1,686)		(1,761)
Amount of decrease (increase) in Customer Advances			$ 75
Percent decrease (increase) in Customer Advances			(4.00%)
Contract with Customer, Asset, Net, Current	3,914		$ 3,914		$ 1,704
Amount of increase (decrease) in net contract assets (liabilities)			$ 2,210
Percent increase (decrease) in net contract assets (liabilities)			130.00%
Innovation Systems net contract assets	1,300		$ 1,300
Change in Contract with Customer, Liability [Abstract]
Contract with Customer, Liability, Revenue Recognized	$ 168	$ 162	$ 1,200	$ 1,000