Basis of Presentation (Unaudited) Backlog and Contract Assets and Liabilities (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Change in Contract with Customer, Liability [Abstract]
Contract with Customer, Liability, Revenue Recognized	$ 232	$ 209	$ 1,500	$ 1,200
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Amount	$ 81,300		$ 81,300
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Explanation			We expect to recognize approximately 35 percent and 55 percent of our September 30, 2020 backlog as revenue over the next 12 and 24 months, respectively, with the remainder to be recognized thereafter.