Revenue - Revenue by Customer (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 04, 2021	Jun. 28, 2020	Jul. 04, 2021	Jun. 28, 2020
Revenue [Line Items]
Revenue	$ 9,220	$ 9,264	$ 18,609	$ 18,013
U.S. Government - DoD
Revenue [Line Items]
Revenue	5,276	5,067	10,417	9,912
U.S. Government - Non-DoD
Revenue [Line Items]
Revenue	1,298	1,151	2,550	2,339
U.S. Government - Foreign Military Sales (FMS)
Revenue [Line Items]
Revenue	127	215	303	384
Total U.S. government
Revenue [Line Items]
Revenue	6,701	6,433	13,270	12,635
U.S. commercial
Revenue [Line Items]
Revenue	1,061	1,211	2,042	2,160
Non-U.S. government
Revenue [Line Items]
Revenue	936	785	1,989	1,624
Non-U.S. commercial
Revenue [Line Items]
Revenue	522	835	1,308	1,594
Aerospace
Revenue [Line Items]
Revenue	1,622	1,974	3,509	3,665
Aerospace | U.S. Government - DoD
Revenue [Line Items]
Revenue	72	52	130	213
Aerospace | U.S. Government - Non-DoD
Revenue [Line Items]
Revenue	0	0	0	0
Aerospace | U.S. Government - Foreign Military Sales (FMS)
Revenue [Line Items]
Revenue	18	52	37	70
Aerospace | Total U.S. government
Revenue [Line Items]
Revenue	90	104	167	283
Aerospace | U.S. commercial
Revenue [Line Items]
Revenue	982	1,032	1,839	1,812
Aerospace | Non-U.S. government
Revenue [Line Items]
Revenue	50	53	240	74
Aerospace | Non-U.S. commercial
Revenue [Line Items]
Revenue	500	785	1,263	1,496
Marine Systems
Revenue [Line Items]
Revenue	2,536	2,471	5,019	4,717
Marine Systems | U.S. Government - DoD
Revenue [Line Items]
Revenue	2,492	2,390	4,912	4,549
Marine Systems | U.S. Government - Non-DoD
Revenue [Line Items]
Revenue	0	1	4	2
Marine Systems | U.S. Government - Foreign Military Sales (FMS)
Revenue [Line Items]
Revenue	41	51	97	100
Marine Systems | Total U.S. government
Revenue [Line Items]
Revenue	2,533	2,442	5,013	4,651
Marine Systems | U.S. commercial
Revenue [Line Items]
Revenue	1	27	2	60
Marine Systems | Non-U.S. government
Revenue [Line Items]
Revenue	0	2	2	5
Marine Systems | Non-U.S. commercial
Revenue [Line Items]
Revenue	2	0	2	1
Combat Systems
Revenue [Line Items]
Revenue	1,899	1,754	3,719	3,462
Combat Systems | U.S. Government - DoD
Revenue [Line Items]
Revenue	954	930	1,870	1,818
Combat Systems | U.S. Government - Non-DoD
Revenue [Line Items]
Revenue	3	3	5	6
Combat Systems | U.S. Government - Foreign Military Sales (FMS)
Revenue [Line Items]
Revenue	62	99	149	188
Combat Systems | Total U.S. government
Revenue [Line Items]
Revenue	1,019	1,032	2,024	2,012
Combat Systems | U.S. commercial
Revenue [Line Items]
Revenue	42	86	108	141
Combat Systems | Non-U.S. government
Revenue [Line Items]
Revenue	822	618	1,554	1,281
Combat Systems | Non-U.S. commercial
Revenue [Line Items]
Revenue	16	18	33	28
Technologies
Revenue [Line Items]
Revenue	3,163	3,065	6,362	6,169
Technologies | U.S. Government - DoD
Revenue [Line Items]
Revenue	1,758	1,695	3,505	3,332
Technologies | U.S. Government - Non-DoD
Revenue [Line Items]
Revenue	1,295	1,147	2,541	2,331
Technologies | U.S. Government - Foreign Military Sales (FMS)
Revenue [Line Items]
Revenue	6	13	20	26
Technologies | Total U.S. government
Revenue [Line Items]
Revenue	3,059	2,855	6,066	5,689
Technologies | U.S. commercial
Revenue [Line Items]
Revenue	36	66	93	147
Technologies | Non-U.S. government
Revenue [Line Items]
Revenue	64	112	193	264
Technologies | Non-U.S. commercial
Revenue [Line Items]
Revenue	$ 4	$ 32	$ 10	$ 69