PENSION AND OTHER POSTRETIREMENT BENEFITS - Roll Forward of Projected Benefit Obligations (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jan. 03, 2020	Jan. 01, 2021	Jun. 28, 2019	Jun. 29, 2018
Change in benefit obligation
Benefit obligation at beginning of fiscal year		$ 10,637	$ 6,344
Benefit obligation assumed in L3Harris Merger	$ 4,630	0
Service cost	43	67
Interest cost	154	283
Actuarial loss	308	1,059
Amendments	(292)	9
Benefits paid	(363)	(595)
Settlements	(5)	0
Special termination benefits	0	1
Expenses paid	(43)	(42)
Curtailments	(35)	0
Foreign currency exchange rate changes	3	11
Plan participants’ contributions	1	2
Divestiture	(108)	0
Benefit obligation at end of fiscal year	10,637	11,432		$ 6,344
Pension
Change in benefit obligation
Benefit obligation at beginning of fiscal year		10,268	6,123
Benefit obligation assumed in L3Harris Merger	4,474	0
Service cost	42	65	36	39
Interest cost	149	273	209	195
Actuarial loss	301	1,035
Amendments	(292)	1
Benefits paid	(342)	(569)
Settlements	(5)	0
Special termination benefits	0	1
Expenses paid	(43)	(42)
Curtailments	(35)	0
Foreign currency exchange rate changes	3	11
Plan participants’ contributions	1	2
Divestiture	(108)	0
Benefit obligation at end of fiscal year	10,268	11,045		6,123
Other Benefits
Change in benefit obligation
Benefit obligation at beginning of fiscal year		369	221
Benefit obligation assumed in L3Harris Merger	156	0
Service cost	1	2	0	1
Interest cost	5	10	$ 8	7
Actuarial loss	7	24
Amendments	0	8
Benefits paid	(21)	(26)
Settlements	0	0
Special termination benefits	0	0
Expenses paid	0	0
Curtailments	0	0
Foreign currency exchange rate changes	0	0
Plan participants’ contributions	0	0
Divestiture	0	0
Benefit obligation at end of fiscal year	$ 369	$ 387		$ 221