Business Segment Information - Total Assets by Segment (Details) - USD ($) $ in Millions	Jul. 02, 2021	Jan. 01, 2021
Segment Reporting Information [Line Items]
Assets	$ 36,064	$ 36,960
Identifiable intangibles assets acquired	6,958	7,908
Operating segments | Integrated Mission Systems
Segment Reporting Information [Line Items]
Assets	9,152	8,906
Operating segments | Space and Airborne Systems
Segment Reporting Information [Line Items]
Assets	7,058	6,943
Operating segments | Communication Systems
Segment Reporting Information [Line Items]
Assets	5,871	5,746
Operating segments | Aviation Systems
Segment Reporting Information [Line Items]
Assets	4,042	5,026
Corporate
Segment Reporting Information [Line Items]
Assets	9,941	10,339
Corporate | Exelis
Segment Reporting Information [Line Items]
Identifiable intangibles assets acquired	$ 7,000	$ 7,900