Summary of Significant Accounting Policies Backlog and Contract Assets and Liabilities (Details 5) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue, Remaining Performance Obligation, Amount	$ 76,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Explanation	Of our December 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.
Unbilled Receivables, Current	$ 5,492	$ 5,140
Amount of increase (decrease) in Unbilled Receivables	$ 352
Percent increase (decrease) in Unbilled Receivables	7.00%
Contract with Customer, Liability, Current	$ (3,026)	(2,517)
Amount of decrease (increase) in Contract with Customer, Liability, Current	$ (509)
Percent decrease (increase) in Contract with Customer, Liability, Current	20.00%
Contract with Customer, Asset, Net, Current	$ 2,466	2,623
Amount of increase (decrease) in net contract assets (liabilities)	$ (157)
Percent increase (decrease) in net contract assets (liabilities)	(6.00%)
Contract with Customer, Liability, Revenue Recognized	$ 2,000	$ 1,600	$ 1,300