Segment Information - Summary of Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 9,761	$ 9,094	$ 28,577	$ 25,815
Operating earnings	1,216	1,135	3,320	3,231
Aerospace
Segment Reporting Information [Line Items]
Revenue	2,495	2,031	6,871	5,751
Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,740	1,523	5,035	4,497
Information Technology
Segment Reporting Information [Line Items]
Revenue	2,071	2,307	6,398	5,887
Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,220	1,230	3,655	3,475
Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,235	2,003	6,618	6,205
Operating Segments | Aerospace
Segment Reporting Information [Line Items]
Revenue	2,495	2,031	6,871	5,751
Operating earnings	393	376	1,052	1,108
Operating Segments | Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,740	1,523	5,035	4,497
Operating earnings	264	241	712	701
Operating Segments | Information Technology
Segment Reporting Information [Line Items]
Revenue	2,071	2,307	6,398	5,887
Operating earnings	146	157	456	414
Operating Segments | Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,220	1,230	3,655	3,475
Operating earnings	185	179	495	478
Operating Segments | Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,235	2,003	6,618	6,205
Operating earnings	209	169	586	548
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Operating earnings	$ 19	$ 13	$ 19	$ (18)