BUSINESS SEGMENTS - Additional Information (Details) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 27, 2019 segment	Jan. 03, 2020 USD ($) segment	Jun. 28, 2019 USD ($)	Jun. 29, 2018 USD ($)	Jun. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		4
Number of operating segments | segment	4
Amortization of intangible assets, debt premium, debt discount and debt issuance costs | $		$ 285	$ 120	$ 116	$ 125
Geographic Concentration Risk | Total Revenue
Segment Reporting Information [Line Items]
Concentration risk percentage		5.00%	5.00%	5.00%	5.00%
Government Contracts Concentration Risk | Total Revenue
Segment Reporting Information [Line Items]
Concentration risk percentage		73.00%	77.00%	75.00%	74.00%
Product Concentration Risk | Total Revenue
Segment Reporting Information [Line Items]
Concentration risk percentage		21.00%	22.00%	23.00%	25.00%
Export revenue | $		$ 2,000	$ 1,500	$ 1,400	$ 1,500
Product Concentration Risk | Sales revenue service | Integrated Mission Systems
Segment Reporting Information [Line Items]
Concentration risk percentage		32.00%
Product Concentration Risk | Sales revenue service | Space and Airborne Systems
Segment Reporting Information [Line Items]
Concentration risk percentage		16.00%
Product Concentration Risk | Sales revenue service | Communication Systems
Segment Reporting Information [Line Items]
Concentration risk percentage		15.00%
Product Concentration Risk | Sales revenue service | Aviation Systems
Segment Reporting Information [Line Items]
Concentration risk percentage		39.00%