Segment Information (Details 4) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Concentration Risk, Percentage									100.00%	100.00%	100.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 25,661	$ 22,552	$ 21,411
Concentration Risk, Percentage									85.00%	87.00%	87.00%
Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 1,666	$ 1,461	$ 1,212
Concentration Risk, Percentage									6.00%	5.00%	5.00%
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 2,768	$ 1,991	$ 2,083
Concentration Risk, Percentage									9.00%	8.00%	8.00%
Aerospace Systems [Member] | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 11,528	$ 10,676	$ 9,421
Concentration Risk, Percentage									89.00%	90.00%	89.00%
Aerospace Systems [Member] | Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 705	$ 649	$ 579
Concentration Risk, Percentage									6.00%	6.00%	5.00%
Aerospace Systems [Member] | All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 666	$ 511	$ 613
Concentration Risk, Percentage									5.00%	4.00%	6.00%
Aerospace Systems [Member] | Intersegment sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 197	$ 295	$ 240
Aerospace Systems [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 13,096	$ 12,131	$ 10,853
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Innovation Systems | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 2,534	$ 0	$ 0
Concentration Risk, Percentage									80.00%	0.00%	0.00%
Innovation Systems | Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 151	$ 0	$ 0
Concentration Risk, Percentage									5.00%	0.00%	0.00%
Innovation Systems | All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 464	$ 0	$ 0
Concentration Risk, Percentage									15.00%	0.00%	0.00%
Innovation Systems | Intersegment sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 127	$ 0	$ 0
Innovation Systems | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 3,276	$ 0	$ 0
Concentration Risk, Percentage									100.00%	0.00%	0.00%
Mission Systems [Member] | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 8,917	$ 8,976	$ 8,870
Concentration Risk, Percentage									85.00%	86.00%	86.00%
Mission Systems [Member] | Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 659	$ 671	$ 514
Concentration Risk, Percentage									6.00%	6.00%	5.00%
Mission Systems [Member] | All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 988	$ 869	$ 902
Concentration Risk, Percentage									9.00%	8.00%	9.00%
Mission Systems [Member] | Intersegment sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 1,145	$ 954	$ 875
Mission Systems [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 11,709	$ 11,470	$ 11,161
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Technology Services [Member] | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 2,682	$ 2,900	$ 3,120
Concentration Risk, Percentage									77.00%	79.00%	82.00%
Technology Services [Member] | Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 151	$ 141	$ 119
Concentration Risk, Percentage									4.00%	4.00%	3.00%
Technology Services [Member] | All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 650	$ 611	$ 568
Concentration Risk, Percentage									19.00%	17.00%	15.00%
Technology Services [Member] | Intersegment sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 814	$ 1,035	$ 958
Technology Services [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 4,297	$ 4,687	$ 4,765
Concentration Risk, Percentage									100.00%	100.00%	100.00%