Restructuring and Other Exit Costs - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Oct. 02, 2020	Jul. 03, 2020	Sep. 27, 2019	Oct. 02, 2020	Sep. 27, 2019	Jan. 03, 2020	Jun. 28, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 24
Restructuring liabilities	$ 40			40		$ 65
COVID-19-Related Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Restructuring liabilities	10			10
COVID-19-Related Restructuring Costs | Aviation Systems
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2			16
COVID-19-Related Restructuring Costs | Communication Systems
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 1
Other Restructuring and Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges				0
Restructuring liabilities	6			6		$ 7
Remaining lease term (less than)							3 years
L3Harris
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	$ 7	$ 111	7	$ 111
Restructuring liabilities	$ 24			$ 24