Summary of Significant Accounting Policies Update - Contracts accounted for under cumulative catch-up method (Details) - Cumulative catch-up method - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Use of Estimates
Cumulative Catch-Up Adjustments	$ 196	$ 5	$ 83
Change in Accounting Estimate Financial Effect Increase In Net Income	$ 149	$ 3	$ 52
Change in Accounting Estimate Financial Effect Increase in Earnings Per Share Diluted	$ 0.59	$ 0.01	$ 0.19
Gross favorable adjustments	$ 249	$ 92	$ 106
Gross unfavorable adjustments	53	87	$ 23
Gross favorable adjustment related to Bell segment	145
Gross unfavorable program profit adjustments related to the Tactical Armoured Patrol Vehicle Program		$ 44
Revenue recognized from performance obligations satisfied in prior periods	$ 190