Segment Information (Unaudited) (Details 4) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue, Geographic Location [Line Items]
Sales	$ 8,456	$ 7,119	$ 16,645	$ 13,854
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
United States
Revenue, Geographic Location [Line Items]
Sales	$ 7,155	$ 5,999	$ 14,127	$ 11,864
Concentration Risk, Percentage	84.00%	84.00%	85.00%	85.00%
United States | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,948	$ 2,837	$ 6,004	$ 5,787
Concentration Risk, Percentage	88.00%	86.00%	88.00%	89.00%
United States | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,179	$ 296	$ 2,308	$ 296
Concentration Risk, Percentage	84.00%	77.00%	83.00%	77.00%
United States | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,387	$ 2,193	$ 4,588	$ 4,413
Concentration Risk, Percentage	84.00%	85.00%	85.00%	85.00%
United States | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 641	$ 673	$ 1,227	$ 1,368
Concentration Risk, Percentage	74.00%	78.00%	74.00%	77.00%
Asia/Pacific
Revenue, Geographic Location [Line Items]
Sales	$ 484	$ 469	$ 952	$ 783
Concentration Risk, Percentage	6.00%	7.00%	6.00%	6.00%
Asia/Pacific | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 220	$ 249	$ 459	$ 378
Concentration Risk, Percentage	7.00%	8.00%	7.00%	6.00%
Asia/Pacific | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 48	$ 24	$ 93	$ 24
Concentration Risk, Percentage	3.00%	6.00%	3.00%	6.00%
Asia/Pacific | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 154	$ 160	$ 300	$ 313
Concentration Risk, Percentage	5.00%	6.00%	5.00%	6.00%
Asia/Pacific | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 62	$ 36	$ 100	$ 68
Concentration Risk, Percentage	7.00%	4.00%	6.00%	4.00%
All other
Revenue, Geographic Location [Line Items]
Sales	$ 817	$ 651	$ 1,566	$ 1,207
Concentration Risk, Percentage	10.00%	9.00%	9.00%	9.00%
All other | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 170	$ 200	$ 325	$ 342
Concentration Risk, Percentage	5.00%	6.00%	5.00%	5.00%
All other | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 179	$ 67	$ 381	$ 67
Concentration Risk, Percentage	13.00%	17.00%	14.00%	17.00%
All other | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 305	$ 227	$ 526	$ 453
Concentration Risk, Percentage	11.00%	9.00%	10.00%	9.00%
All other | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 163	$ 157	$ 334	$ 345
Concentration Risk, Percentage	19.00%	18.00%	20.00%	19.00%
Intersegment sales | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 52	$ 51	$ 98	$ 110
Intersegment sales | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	92	13	154	13
Intersegment sales | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	282	294	600	578
Intersegment sales | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	178	182	360	411
Operating Segments [Member] | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 3,390	$ 3,337	$ 6,886	$ 6,617
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,498	$ 400	$ 2,936	$ 400
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 3,128	$ 2,874	$ 6,014	$ 5,757
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,044	$ 1,048	$ 2,021	$ 2,192
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%