Business Segment Information - Assets by Segment (Details) - USD ($) $ in Millions	Dec. 28, 2018	Jun. 29, 2018
Segment Reporting Information [Line Items]
Assets	$ 9,852	$ 9,851
Identifiable intangible assets	930	989
Operating Segments | Communication Systems
Segment Reporting Information [Line Items]
Assets	1,578	1,567
Operating Segments | Electronic Systems
Segment Reporting Information [Line Items]
Assets	4,196	4,174
Operating Segments | Space and Intelligence Systems
Segment Reporting Information [Line Items]
Assets	2,242	2,193
Corporate
Segment Reporting Information [Line Items]
Assets	1,836	1,917
Corporate | Exelis
Segment Reporting Information [Line Items]
Identifiable intangible assets	$ 923	$ 974