Business Segment Information - Assets by Segment (Details) - USD ($) $ in Millions	Sep. 28, 2018	Jun. 29, 2018
Segment Reporting Information [Line Items]
Assets	$ 9,889	$ 9,851
Identifiable intangible assets	960	989
Operating Segments | Communication Systems
Segment Reporting Information [Line Items]
Assets	1,556	1,567
Operating Segments | Electronic Systems
Segment Reporting Information [Line Items]
Assets	4,204	4,174
Operating Segments | Space and Intelligence Systems
Segment Reporting Information [Line Items]
Assets	2,220	2,193
Corporate
Segment Reporting Information [Line Items]
Assets	1,909	1,917
Corporate | Exelis
Segment Reporting Information [Line Items]
Identifiable intangible assets	$ 949	$ 974