Segment Information - Summary of Financial Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Revenue	$ 8,749	$ 9,261
Operating Earnings	941	1,014
Aerospace
Segment Reporting Information [Line Items]
Revenue	1,691	2,240
Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,708	1,636
Information Technology
Segment Reporting Information [Line Items]
Revenue	1,988	2,169
Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,116	1,158
Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,246	2,058
Operating Segments | Aerospace
Segment Reporting Information [Line Items]
Revenue	1,691	2,240
Operating Earnings	240	328
Operating Segments | Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,708	1,636
Operating Earnings	223	206
Operating Segments | Information Technology
Segment Reporting Information [Line Items]
Revenue	1,988	2,169
Operating Earnings	150	156
Operating Segments | Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,116	1,158
Operating Earnings	148	148
Operating Segments | Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,246	2,058
Operating Earnings	184	180
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0
Operating Earnings	$ (4)	$ (4)