BUSINESS SEGMENT INFORMATION - Revenues and Income From Continuing Operations by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 01, 2022	Apr. 02, 2021
Segment Reporting Information [Line Items]
Revenue from product sales and services	$ 4,103	$ 4,567
Unallocated Items:
Unallocated corporate department expense, net	(7)	(33)
L3Harris Merger-related transaction, integration and other expenses and losses	(20)	(21)
Amortization of acquisition-related intangibles	(152)	(164)
Business divestiture-related losses	0	(15)
Impairment of goodwill and other assets	0	(62)
Other items	(1)	(7)
FAS/CAS pension adjustment	22	30
Total unallocated expenses	(158)	(272)
Non-operating income	106	117
Net interest expense	(68)	(66)
Income from continuing operations before income taxes	536	527
Accrual for value added tax obligation		15
FAS pension service cost	(11)	(18)
Less: CAS pension cost	(33)	(48)
FAS/CAS pension adjustment	22	30
Non-service FAS pension income	110	111
Net FAS/CAS pension adjustment	132	141
Operating segments
Income from Continuing Operations before Income Taxes
Segment Operating Income:	656	748
Operating segments | Integrated Mission Systems
Segment Reporting Information [Line Items]
Revenue from product sales and services	1,721	1,751
Income from Continuing Operations before Income Taxes
Segment Operating Income:	255	234
Operating segments | Space & Airborne Systems
Segment Reporting Information [Line Items]
Revenue from product sales and services	1,450	1,460
Income from Continuing Operations before Income Taxes
Segment Operating Income:	172	192
Operating segments | Communication Systems
Segment Reporting Information [Line Items]
Revenue from product sales and services	963	1,112
Income from Continuing Operations before Income Taxes
Segment Operating Income:	229	270
Other non-reportable businesses
Segment Reporting Information [Line Items]
Revenue from product sales and services	0	284
Income from Continuing Operations before Income Taxes
Segment Operating Income:	0	52
Corporate eliminations
Segment Reporting Information [Line Items]
Revenue from product sales and services	$ (31)	$ (40)