Business Segments - Assets by Segment (Details) - USD ($) $ in Millions	Mar. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Assets	$ 10,070	$ 10,090
Identifiable intangible assets	1,019	1,104
Operating Segments | Communication Systems
Segment Reporting Information [Line Items]
Assets	1,592	1,534
Operating Segments | Electronic Systems
Segment Reporting Information [Line Items]
Assets	4,177	4,094
Operating Segments | Space and Intelligence Systems
Segment Reporting Information [Line Items]
Assets	2,190	2,117
Corporate
Segment Reporting Information [Line Items]
Assets	2,111	2,345
Corporate | Exelis
Segment Reporting Information [Line Items]
Identifiable intangible assets	$ 1,000	$ 1,000