Segment Information - Summary of Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Segment Reporting Information [Line Items]
Revenue	$ 9,431	$ 9,761	$ 27,444	$ 28,577
Operating Earnings	1,084	1,216	2,866	3,320
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Operating Earnings	(6)	19	(14)	19
Aerospace
Segment Reporting Information [Line Items]
Revenue	1,975	2,495	5,640	6,871
Aerospace | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,975	2,495	5,640	6,871
Operating Earnings	283	393	682	1,052
Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,801	1,740	5,263	5,035
Combat Systems | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,801	1,740	5,263	5,035
Operating Earnings	270	264	732	712
Information Technology
Segment Reporting Information [Line Items]
Revenue	2,029	2,071	5,901	6,398
Information Technology | Operating Segments
Segment Reporting Information [Line Items]
Revenue	2,029	2,071	5,901	6,398
Operating Earnings	146	146	379	456
Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,221	1,220	3,518	3,655
Mission Systems | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,221	1,220	3,518	3,655
Operating Earnings	168	185	480	495
Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,405	2,235	7,122	6,618
Marine Systems | Operating Segments
Segment Reporting Information [Line Items]
Revenue	2,405	2,235	7,122	6,618
Operating Earnings	$ 223	$ 209	$ 607	$ 586