Business Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 4,668	$ 4,445	$ 9,235	$ 9,071
Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(49)	(47)	(95)	(88)
Integrated Mission Systems | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue	1,494	1,331	2,945	2,701
Integrated Mission Systems | Transferred over time | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	14	13	29	25
Integrated Mission Systems | Transferred over time | United States
Disaggregation of Revenue [Line Items]
Revenue	1,034	1,026	2,054	2,119
Integrated Mission Systems | Transferred over time | International
Disaggregation of Revenue [Line Items]
Revenue	446	292	862	557
Integrated Mission Systems | Transferred over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	1,147	997	2,239	2,021
Integrated Mission Systems | Transferred over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	333	321	677	655
Integrated Mission Systems | Transferred over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	1,020	856	2,027	1,807
Integrated Mission Systems | Transferred over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	460	462	889	869
Space and Airborne Systems | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue	1,287	1,249	2,523	2,441
Space and Airborne Systems | Transferred over time | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	2	3	4	6
Space and Airborne Systems | Transferred over time | United States
Disaggregation of Revenue [Line Items]
Revenue	1,102	1,049	2,162	2,050
Space and Airborne Systems | Transferred over time | International
Disaggregation of Revenue [Line Items]
Revenue	183	197	357	385
Space and Airborne Systems | Transferred over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	740	701	1,455	1,370
Space and Airborne Systems | Transferred over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	545	545	1,064	1,065
Space and Airborne Systems | Transferred over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	733	674	1,416	1,333
Space and Airborne Systems | Transferred over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	552	572	1,103	1,102
Communication Systems | Transferred at point in time and over time
Disaggregation of Revenue [Line Items]
Revenue	1,127	1,112	2,239	2,206
Communication Systems | Transferred at point in time and over time | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	14	11	25	19
Communication Systems | Transferred at point in time and over time | United States
Disaggregation of Revenue [Line Items]
Revenue	786	835	1,618	1,664
Communication Systems | Transferred at point in time and over time | International
Disaggregation of Revenue [Line Items]
Revenue	327	266	596	523
Communication Systems | Transferred at point in time and over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	954	945	1,894	1,858
Communication Systems | Transferred at point in time and over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	159	156	320	329
Communication Systems | Transferred at point in time and over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	783	748	1,512	1,488
Communication Systems | Transferred at point in time and over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	330	353	702	699
Aviation Systems | Transferred at point in time and over time
Disaggregation of Revenue [Line Items]
Revenue	809	800	1,623	1,811
Aviation Systems | Transferred at point in time and over time | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	19	20	37	38
Aviation Systems | Transferred at point in time and over time | United States
Disaggregation of Revenue [Line Items]
Revenue	679	676	1,361	1,408
Aviation Systems | Transferred at point in time and over time | International
Disaggregation of Revenue [Line Items]
Revenue	111	104	225	365
Aviation Systems | Transferred at point in time and over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	641	610	1,280	1,439
Aviation Systems | Transferred at point in time and over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	149	170	306	334
Aviation Systems | Transferred at point in time and over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	520	515	1,056	1,179
Aviation Systems | Transferred at point in time and over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	$ 270	$ 265	$ 530	$ 594