PENSION AND OTHER POSTRETIREMENT BENEFITS - Balance Sheet Information (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jan. 03, 2020	Jun. 28, 2019	Jun. 29, 2018	Jun. 30, 2017
Change in plan assets
Plan assets at beginning of fiscal year	$ 5,159	$ 5,305
Plan assets at end of fiscal year	8,892	5,159	$ 5,305
Defined benefit plan with accumulated benefit obligation in excess of plan assets
Projected benefit obligation	9,670	6,041	5,694
Accumulated benefit obligation	9,656	6,041	5,694
Fair value of plan assets	7,931	4,864	5,004
Pension
Change in benefit obligation
Benefit obligation at beginning of fiscal year	6,123	5,774	6,140
Benefit obligation assumed in L3Harris Merger	4,474	0	0
Service cost	42	36	39	$ 58
Interest cost	149	209	195	184
Actuarial loss (gain)	301	514	(169)
Amendments	(292)	3	2
Benefits paid	(342)	(381)	(402)
Settlements	(5)	0	0
Expenses paid	(43)	(30)	(35)
Curtailments	(35)	1	0
Foreign currency exchange rate changes	3	(3)	4
Plan participants' contributions	1	0	0
Divestiture	(108)	0	0
Benefit obligation at end of fiscal year	10,268	6,123	5,774	6,140
Change in plan assets
Plan assets at beginning of fiscal year	4,958	5,098	4,921
Plan assets acquired in L3Harris Merger	3,183	0	0
Actual return on plan assets	548	271	307
Employer contributions	406	3	303
Benefits paid	(342)	(381)	(402)
Settlements	(5)	0	0
Expenses paid	(43)	(30)	(35)
Foreign currency exchange rate changes	4	(3)	4
Plan participants' contributions	1	0	0
Divestiture	(92)	0	0
Plan assets at end of fiscal year	8,618	4,958	5,098	4,921
Funded status	(1,650)	(1,165)	(676)
Other Benefits
Change in benefit obligation
Benefit obligation at beginning of fiscal year	221	233	265
Benefit obligation assumed in L3Harris Merger	156	0	0
Service cost	1	0	1	1
Interest cost	5	8	7	8
Actuarial loss (gain)	7	(1)	(22)
Amendments	0	0	0
Benefits paid	(21)	(19)	(18)
Settlements	0	0	0
Expenses paid	0	0	0
Curtailments	0	0	0
Foreign currency exchange rate changes	0	0	0
Plan participants' contributions	0	0	0
Divestiture	0	0	0
Benefit obligation at end of fiscal year	369	221	233	265
Change in plan assets
Plan assets at beginning of fiscal year	201	207	212
Plan assets acquired in L3Harris Merger	68	0	0
Actual return on plan assets	18	11	14
Employer contributions	8	2	(1)
Benefits paid	(21)	(19)	(18)
Settlements	0	0	0
Expenses paid	0	0	0
Foreign currency exchange rate changes	0	0	0
Plan participants' contributions	0	0	0
Divestiture	0	0	0
Plan assets at end of fiscal year	274	201	207	$ 212
Funded status	$ (95)	$ (20)	$ (26)