Business Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 03, 2020	Jun. 28, 2019	Jul. 03, 2020	Jun. 28, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 4,445	$ 1,865	$ 9,071	$ 3,593
Integrated Mission Systems | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue	1,331	11	2,701	25
Integrated Mission Systems | Transferred over time | United States
Disaggregation of Revenue [Line Items]
Revenue	1,038	6	2,143	15
Integrated Mission Systems | Transferred over time | International
Disaggregation of Revenue [Line Items]
Revenue	293	5	558	10
Integrated Mission Systems | Transferred over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	998	11	2,023	25
Integrated Mission Systems | Transferred over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	333	0	678	0
Integrated Mission Systems | Transferred over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	858	4	1,807	12
Integrated Mission Systems | Transferred over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	473	7	894	13
Space and Airborne Systems | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue	1,249	1,019	2,441	1,975
Space and Airborne Systems | Transferred over time | United States
Disaggregation of Revenue [Line Items]
Revenue	1,054	886	2,057	1,732
Space and Airborne Systems | Transferred over time | International
Disaggregation of Revenue [Line Items]
Revenue	195	133	384	243
Space and Airborne Systems | Transferred over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	702	601	1,372	1,132
Space and Airborne Systems | Transferred over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	547	418	1,069	843
Space and Airborne Systems | Transferred over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	674	590	1,332	1,162
Space and Airborne Systems | Transferred over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	575	429	1,109	813
Communication Systems | Transferred at point in time and over time
Disaggregation of Revenue [Line Items]
Revenue	1,112	609	2,206	1,189
Communication Systems | Transferred at point in time and over time | United States
Disaggregation of Revenue [Line Items]
Revenue	844	355	1,678	702
Communication Systems | Transferred at point in time and over time | International
Disaggregation of Revenue [Line Items]
Revenue	268	254	528	487
Communication Systems | Transferred at point in time and over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	951		1,869
Communication Systems | Transferred at point in time and over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	161		337
Communication Systems | Transferred at point in time and over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	749		1,489
Communication Systems | Transferred at point in time and over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	363		717
Aviation Systems | Transferred at point in time and over time
Disaggregation of Revenue [Line Items]
Revenue	800	186	1,811	330
Aviation Systems | Transferred at point in time and over time | United States
Disaggregation of Revenue [Line Items]
Revenue	696	178	1,445	321
Aviation Systems | Transferred at point in time and over time | International
Disaggregation of Revenue [Line Items]
Revenue	104	8	366	9
Aviation Systems | Transferred at point in time and over time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	627	164	1,468	286
Aviation Systems | Transferred at point in time and over time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	173	22	343	44
Aviation Systems | Transferred at point in time and over time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	514	180	1,178	320
Aviation Systems | Transferred at point in time and over time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	$ 286	$ 6	$ 633	$ 10