Segment Information - Summary of Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Segment Reporting Information [Line Items]
Revenue	$ 9,555	$ 9,186	$ 18,816	$ 16,721
Operating earnings	1,090	1,088	2,104	2,096
Aerospace
Segment Reporting Information [Line Items]
Revenue	2,136	1,895	4,376	3,720
Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,659	1,534	3,295	2,974
Information Technology
Segment Reporting Information [Line Items]
Revenue	2,158	2,442	4,327	3,580
Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,277	1,147	2,435	2,245
Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,325	2,168	4,383	4,202
Operating Segments | Aerospace
Segment Reporting Information [Line Items]
Revenue	2,136	1,895	4,376	3,720
Operating earnings	331	386	659	732
Operating Segments | Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,659	1,534	3,295	2,974
Operating earnings	242	236	448	460
Operating Segments | Information Technology
Segment Reporting Information [Line Items]
Revenue	2,158	2,442	4,327	3,580
Operating earnings	154	156	310	257
Operating Segments | Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,277	1,147	2,435	2,245
Operating earnings	162	153	310	299
Operating Segments | Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,325	2,168	4,383	4,202
Operating earnings	197	195	377	379
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Operating earnings	$ 4	$ (38)	$ 0	$ (31)