Business Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2020	Sep. 27, 2019	Oct. 02, 2020	Sep. 27, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 4,463	$ 4,431	$ 13,534	$ 8,024
Integrated Mission Systems | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue	1,372	1,292	4,073	1,317
Integrated Mission Systems | Transferred over time | United States
Disaggregation of Revenue [Line Items]
Revenue	1,097	1,071	3,240	1,086
Integrated Mission Systems | Transferred over time | International
Disaggregation of Revenue [Line Items]
Revenue	275	221	833	231
Integrated Mission Systems | Transferred over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	1,041	1,010	3,064	1,035
Integrated Mission Systems | Transferred over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	331	282	1,009	282
Integrated Mission Systems | Transferred over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	910	882	2,717	894
Integrated Mission Systems | Transferred over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	462	410	1,356	423
Space and Airborne Systems | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue	1,249	1,173	3,690	3,148
Space and Airborne Systems | Transferred over time | United States
Disaggregation of Revenue [Line Items]
Revenue	1,067	1,018	3,124	2,750
Space and Airborne Systems | Transferred over time | International
Disaggregation of Revenue [Line Items]
Revenue	182	155	566	398
Space and Airborne Systems | Transferred over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	703	702	2,075	1,834
Space and Airborne Systems | Transferred over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	546	471	1,615	1,314
Space and Airborne Systems | Transferred over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	674	705	2,006	1,867
Space and Airborne Systems | Transferred over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	575	468	1,684	1,281
Communication Systems | Transferred at point in time and over time
Disaggregation of Revenue [Line Items]
Revenue	1,094	1,032	3,300	2,221
Communication Systems | Transferred at point in time and over time | United States
Disaggregation of Revenue [Line Items]
Revenue	749	721	2,427	1,423
Communication Systems | Transferred at point in time and over time | International
Disaggregation of Revenue [Line Items]
Revenue	345	311	873	798
Communication Systems | Transferred at point in time and over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	935	875	2,804
Communication Systems | Transferred at point in time and over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	159	157	496
Communication Systems | Transferred at point in time and over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	759	679	2,248
Communication Systems | Transferred at point in time and over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	335	353	1,052
Aviation Systems | Transferred at point in time and over time
Disaggregation of Revenue [Line Items]
Revenue	792	948	2,603	1,278
Aviation Systems | Transferred at point in time and over time | United States
Disaggregation of Revenue [Line Items]
Revenue	687	724	2,132	1,045
Aviation Systems | Transferred at point in time and over time | International
Disaggregation of Revenue [Line Items]
Revenue	105	224	471	233
Aviation Systems | Transferred at point in time and over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	646	784	2,114	1,070
Aviation Systems | Transferred at point in time and over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	146	164	489	208
Aviation Systems | Transferred at point in time and over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	511	584	1,689	904
Aviation Systems | Transferred at point in time and over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	$ 281	$ 364	$ 914	$ 374