Basis of Presentation (Unaudited) Backlog and Contract Assets and Liabilities (Details 3) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Change in Contract with Customer, Liability [Abstract]
Contract with Customer, Liability, Revenue Recognized	$ 1,100	$ 781
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Amount	$ 79,300
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Explanation	Of our March 31, 2021 backlog, we expect to recognize approximately 40 percent as revenue over the next 12 months and 60 percent as revenue over the next 24 months, with the remainder to be recognized thereafter.