Segment Information (Details 1) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Number of reportable segments									4
Sales	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Operating income	$ 943	$ 1,172	$ 817	$ 848	$ 672	$ 829	$ 864	$ 853	3,780	3,218	3,277
Operating Segments
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income									3,447	2,903	2,864
Operating Segments | Aerospace Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									13,096	12,131	10,853
Operating income									1,411	1,289	1,198
Operating Segments | Innovation Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									3,276	0	0
Operating income									343	0	0
Operating Segments | Mission Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									11,709	11,470	11,161
Operating income									1,520	1,442	1,468
Operating Segments | Technology Services
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									4,297	4,687	4,765
Operating income									443	449	456
Intersegment sales
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									2,283	2,284	2,073
Operating income									270	277	258
Intersegment sales | Aerospace Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									197	295	240
Operating income									23	33	28
Intersegment sales | Innovation Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									127	0	0
Operating income									1	0	0
Intersegment sales | Mission Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									1,145	954	875
Operating income									165	141	136
Intersegment sales | Technology Services
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									814	1,035	958
Operating income									81	103	94
Net FAS (service)/CAS pension adjustment
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income									613	638	457
Corporate, Non-Segment [Member]
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income									(277)	(319)	(39)
Segment Reconciling Items [Member]
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income									$ (3)	$ (4)	$ (5)