BUSINESS SEGMENTS - Disaggregation of Revenue (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jan. 03, 2020	Dec. 28, 2018	Dec. 31, 2021	Jan. 01, 2021	Jan. 03, 2020	Jun. 28, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 9,263	$ 3,208	$ 17,814	$ 18,194	$ 12,856	$ 6,801
United States
Disaggregation of Revenue [Line Items]
Revenue	8,485		16,234	16,998		6,530
International
Disaggregation of Revenue [Line Items]
Revenue	778		1,580	1,196		271
Integrated Mission Systems | Transferred over Time
Disaggregation of Revenue [Line Items]
Revenue	2,758		5,839	5,538		52
Integrated Mission Systems | Transferred over Time | United States
Disaggregation of Revenue [Line Items]
Revenue	2,120		4,115	4,338		30
Integrated Mission Systems | Transferred over Time | International
Disaggregation of Revenue [Line Items]
Revenue	620		1,656	1,147		22
Integrated Mission Systems | Transferred over Time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	2,115		4,467	4,172		52
Integrated Mission Systems | Transferred over Time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	625		1,304	1,313		0
Integrated Mission Systems | Transferred over Time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	1,893		4,044	3,721		27
Integrated Mission Systems | Transferred over Time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	847		1,727	1,764		25
Integrated Mission Systems | Intersegment | Transferred over Time
Disaggregation of Revenue [Line Items]
Revenue	18		68	53		0
Space & Airborne Systems | Transferred over Time
Disaggregation of Revenue [Line Items]
Revenue	2,377		5,093	4,946		3,711
Space & Airborne Systems | Transferred over Time | United States
Disaggregation of Revenue [Line Items]
Revenue	2,038		4,417	4,180		3,252
Space & Airborne Systems | Transferred over Time | International
Disaggregation of Revenue [Line Items]
Revenue	334		665	751		431
Space & Airborne Systems | Transferred over Time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	1,380		2,921	2,834		2,066
Space & Airborne Systems | Transferred over Time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	992		2,161	2,097		1,617
Space & Airborne Systems | Transferred over Time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	1,349		2,925	2,684		2,244
Space & Airborne Systems | Transferred over Time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	1,023		2,157	2,247		1,439
Space & Airborne Systems | Intersegment | Transferred over Time
Disaggregation of Revenue [Line Items]
Revenue	5		11	15		28
Communication Systems | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenue	2,151		4,287	4,443		2,208
Communication Systems | Transferred at Point in Time | United States
Disaggregation of Revenue [Line Items]
Revenue	1,507		3,001	3,181		1,280
Communication Systems | Transferred at Point in Time | International
Disaggregation of Revenue [Line Items]
Revenue	628		1,232	1,225		927
Communication Systems | Transferred at Point in Time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	1,840		3,631	3,784
Communication Systems | Transferred at Point in Time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	295		602	622
Communication Systems | Transferred at Point in Time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	1,406		2,886	3,102
Communication Systems | Transferred at Point in Time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	729		1,347	1,304
Communication Systems | Intersegment | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenue	16		54	37		1
Aviation Systems | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenue	2,038		2,783	3,448		672
Aviation Systems | Transferred at Point in Time | United States
Disaggregation of Revenue [Line Items]
Revenue	1,472		2,329	2,769		640
Aviation Systems | Transferred at Point in Time | International
Disaggregation of Revenue [Line Items]
Revenue	521		399	603		28
Aviation Systems | Transferred at Point in Time | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	1,664		2,199	2,750		583
Aviation Systems | Transferred at Point in Time | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	329		529	622		85
Aviation Systems | Transferred at Point in Time | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	1,245		1,808	2,258		654
Aviation Systems | Transferred at Point in Time | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	748		920	1,114		14
Aviation Systems | Intersegment | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenue	$ 45		$ 55	$ 76		$ 4