BUSINESS SEGMENTS - Total Assets by Segment (Details) - USD ($) $ in Millions	Jan. 03, 2020	Jun. 28, 2019	Jun. 29, 2018
Segment Reporting Information [Line Items]
Assets	$ 38,336	$ 10,117	$ 9,851
Other intangible assets	8,458	870	989
Corporate eliminations
Segment Reporting Information [Line Items]
Assets	10,112	2,284	2,038
Integrated Mission Systems
Segment Reporting Information [Line Items]
Assets	7,896	87	90
Communication Systems
Segment Reporting Information [Line Items]
Assets	5,930	1,683	1,724
Space and Airborne Systems
Segment Reporting Information [Line Items]
Assets	6,829	5,027	4,953
Aviation Systems
Segment Reporting Information [Line Items]
Assets	7,569	1,036	1,046
Exelis | Corporate eliminations
Segment Reporting Information [Line Items]
Other intangible assets	$ 8,500	$ 869	$ 974