Revenue - Revenue by Customer (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Revenue [Line Items]
Revenue	$ 9,094	$ 7,580	$ 25,815	$ 22,696
Aerospace
Revenue [Line Items]
Revenue	2,031	1,995	5,751	6,147
Combat Systems
Revenue [Line Items]
Revenue	1,523	1,500	4,497	4,201
Information Technology
Revenue [Line Items]
Revenue	2,307	1,068	5,887	3,178
Mission Systems
Revenue [Line Items]
Revenue	1,230	1,086	3,475	3,226
Marine Systems
Revenue [Line Items]
Revenue	2,003	1,931	6,205	5,944
U.S. Government - Department of Defense
Revenue [Line Items]
Revenue	4,371	3,746	12,741	11,184
U.S. Government - Department of Defense | Aerospace
Revenue [Line Items]
Revenue	35	40	165	112
U.S. Government - Department of Defense | Combat Systems
Revenue [Line Items]
Revenue	698	659	1,965	1,928
U.S. Government - Department of Defense | Information Technology
Revenue [Line Items]
Revenue	889	424	2,374	1,269
U.S. Government - Department of Defense | Mission Systems
Revenue [Line Items]
Revenue	854	745	2,360	2,144
U.S. Government - Department of Defense | Marine Systems
Revenue [Line Items]
Revenue	1,895	1,878	5,877	5,731
U.S. Government - Non Department of Defense
Revenue [Line Items]
Revenue	1,480	720	3,681	2,119
U.S. Government - Non Department of Defense | Aerospace
Revenue [Line Items]
Revenue	0	0	0	0
U.S. Government - Non Department of Defense | Combat Systems
Revenue [Line Items]
Revenue	2	2	6	5
U.S. Government - Non Department of Defense | Information Technology
Revenue [Line Items]
Revenue	1,348	582	3,296	1,700
U.S. Government - Non Department of Defense | Mission Systems
Revenue [Line Items]
Revenue	130	135	378	413
U.S. Government - Non Department of Defense | Marine Systems
Revenue [Line Items]
Revenue	0	1	1	1
U.S. Government - Foreign Military Sales
Revenue [Line Items]
Revenue	133	160	424	500
U.S. Government - Foreign Military Sales | Aerospace
Revenue [Line Items]
Revenue	13	8	48	26
U.S. Government - Foreign Military Sales | Combat Systems
Revenue [Line Items]
Revenue	65	93	217	284
U.S. Government - Foreign Military Sales | Information Technology
Revenue [Line Items]
Revenue	8	5	23	16
U.S. Government - Foreign Military Sales | Mission Systems
Revenue [Line Items]
Revenue	10	12	31	34
U.S. Government - Foreign Military Sales | Marine Systems
Revenue [Line Items]
Revenue	37	42	105	140
U.S. Government
Revenue [Line Items]
Revenue	5,984	4,626	16,846	13,803
U.S. Government | Aerospace
Revenue [Line Items]
Revenue	48	48	213	138
U.S. Government | Combat Systems
Revenue [Line Items]
Revenue	765	754	2,188	2,217
U.S. Government | Information Technology
Revenue [Line Items]
Revenue	2,245	1,011	5,693	2,985
U.S. Government | Mission Systems
Revenue [Line Items]
Revenue	994	892	2,769	2,591
U.S. Government | Marine Systems
Revenue [Line Items]
Revenue	1,932	1,921	5,983	5,872
U.S. Commercial
Revenue [Line Items]
Revenue	1,034	1,102	3,197	3,248
U.S. Commercial | Aerospace
Revenue [Line Items]
Revenue	827	958	2,586	2,771
U.S. Commercial | Combat Systems
Revenue [Line Items]
Revenue	59	63	175	166
U.S. Commercial | Information Technology
Revenue [Line Items]
Revenue	41	50	122	176
U.S. Commercial | Mission Systems
Revenue [Line Items]
Revenue	38	25	101	79
U.S. Commercial | Marine Systems
Revenue [Line Items]
Revenue	69	6	213	56
Non U S Government
Revenue [Line Items]
Revenue	915	874	2,867	2,386
Non U S Government | Aerospace
Revenue [Line Items]
Revenue	59	63	212	132
Non U S Government | Combat Systems
Revenue [Line Items]
Revenue	677	668	2,086	1,764
Non U S Government | Information Technology
Revenue [Line Items]
Revenue	21	7	72	17
Non U S Government | Mission Systems
Revenue [Line Items]
Revenue	156	134	489	463
Non U S Government | Marine Systems
Revenue [Line Items]
Revenue	2	2	8	10
Non - U.S. Commercial
Revenue [Line Items]
Revenue	1,161	978	2,905	3,259
Non - U.S. Commercial | Aerospace
Revenue [Line Items]
Revenue	1,097	926	2,740	3,106
Non - U.S. Commercial | Combat Systems
Revenue [Line Items]
Revenue	22	15	48	54
Non - U.S. Commercial | Information Technology
Revenue [Line Items]
Revenue	0	0	0	0
Non - U.S. Commercial | Mission Systems
Revenue [Line Items]
Revenue	42	35	116	93
Non - U.S. Commercial | Marine Systems
Revenue [Line Items]
Revenue	$ 0	$ 2	$ 1	$ 6