Revenue - Revenue by Customer (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Revenue [Line Items]
Revenue	$ 9,761	$ 9,094	$ 28,577	$ 25,815
Aerospace
Revenue [Line Items]
Revenue	2,495	2,031	6,871	5,751
Combat Systems
Revenue [Line Items]
Revenue	1,740	1,523	5,035	4,497
Information Technology
Revenue [Line Items]
Revenue	2,071	2,307	6,398	5,887
Mission Systems
Revenue [Line Items]
Revenue	1,220	1,230	3,655	3,475
Marine Systems
Revenue [Line Items]
Revenue	2,235	2,003	6,618	6,205
U.S. Government - Department of Defense (DoD)
Revenue [Line Items]
Revenue	4,911	4,346	14,525	12,688
U.S. Government - Department of Defense (DoD) | Aerospace
Revenue [Line Items]
Revenue	87	35	262	165
U.S. Government - Department of Defense (DoD) | Combat Systems
Revenue [Line Items]
Revenue	931	698	2,634	1,965
U.S. Government - Department of Defense (DoD) | Information Technology
Revenue [Line Items]
Revenue	875	864	2,725	2,321
U.S. Government - Department of Defense (DoD) | Mission Systems
Revenue [Line Items]
Revenue	861	854	2,529	2,360
U.S. Government - Department of Defense (DoD) | Marine Systems
Revenue [Line Items]
Revenue	2,157	1,895	6,375	5,877
U.S. Government - Non Department of Defense (Non-DoD)
Revenue [Line Items]
Revenue	1,279	1,505	3,924	3,734
U.S. Government - Non Department of Defense (Non-DoD) | Aerospace
Revenue [Line Items]
Revenue	0	0	0	0
U.S. Government - Non Department of Defense (Non-DoD) | Combat Systems
Revenue [Line Items]
Revenue	3	2	9	6
U.S. Government - Non Department of Defense (Non-DoD) | Information Technology
Revenue [Line Items]
Revenue	1,141	1,373	3,511	3,349
U.S. Government - Non Department of Defense (Non-DoD) | Mission Systems
Revenue [Line Items]
Revenue	135	130	403	378
U.S. Government - Non Department of Defense (Non-DoD) | Marine Systems
Revenue [Line Items]
Revenue	0	0	1	1
U.S. Government - Foreign Military Sales (FMS)
Revenue [Line Items]
Revenue	134	133	453	424
U.S. Government - Foreign Military Sales (FMS) | Aerospace
Revenue [Line Items]
Revenue	18	13	47	48
U.S. Government - Foreign Military Sales (FMS) | Combat Systems
Revenue [Line Items]
Revenue	58	65	227	217
U.S. Government - Foreign Military Sales (FMS) | Information Technology
Revenue [Line Items]
Revenue	3	8	12	23
U.S. Government - Foreign Military Sales (FMS) | Mission Systems
Revenue [Line Items]
Revenue	12	10	33	31
U.S. Government - Foreign Military Sales (FMS) | Marine Systems
Revenue [Line Items]
Revenue	43	37	134	105
U.S. Government
Revenue [Line Items]
Revenue	6,324	5,984	18,902	16,846
U.S. Government | Aerospace
Revenue [Line Items]
Revenue	105	48	309	213
U.S. Government | Combat Systems
Revenue [Line Items]
Revenue	992	765	2,870	2,188
U.S. Government | Information Technology
Revenue [Line Items]
Revenue	2,019	2,245	6,248	5,693
U.S. Government | Mission Systems
Revenue [Line Items]
Revenue	1,008	994	2,965	2,769
U.S. Government | Marine Systems
Revenue [Line Items]
Revenue	2,200	1,932	6,510	5,983
U.S. Commercial
Revenue [Line Items]
Revenue	1,598	1,034	4,503	3,197
U.S. Commercial | Aerospace
Revenue [Line Items]
Revenue	1,420	827	3,991	2,586
U.S. Commercial | Combat Systems
Revenue [Line Items]
Revenue	62	59	171	175
U.S. Commercial | Information Technology
Revenue [Line Items]
Revenue	52	41	137	122
U.S. Commercial | Mission Systems
Revenue [Line Items]
Revenue	33	38	107	101
U.S. Commercial | Marine Systems
Revenue [Line Items]
Revenue	31	69	97	213
Non-U.S. Government
Revenue [Line Items]
Revenue	875	915	2,727	2,867
Non-U.S. Government | Aerospace
Revenue [Line Items]
Revenue	64	59	264	212
Non-U.S. Government | Combat Systems
Revenue [Line Items]
Revenue	663	677	1,951	2,086
Non-U.S. Government | Information Technology
Revenue [Line Items]
Revenue	0	21	13	72
Non-U.S. Government | Mission Systems
Revenue [Line Items]
Revenue	145	156	492	489
Non-U.S. Government | Marine Systems
Revenue [Line Items]
Revenue	3	2	7	8
Non-U.S. Commercial
Revenue [Line Items]
Revenue	964	1,161	2,445	2,905
Non-U.S. Commercial | Aerospace
Revenue [Line Items]
Revenue	906	1,097	2,307	2,740
Non-U.S. Commercial | Combat Systems
Revenue [Line Items]
Revenue	23	22	43	48
Non-U.S. Commercial | Information Technology
Revenue [Line Items]
Revenue	0	0	0	0
Non-U.S. Commercial | Mission Systems
Revenue [Line Items]
Revenue	34	42	91	116
Non-U.S. Commercial | Marine Systems
Revenue [Line Items]
Revenue	$ 1	$ 0	$ 4	$ 1