Segment Information (Unaudited) (Details 4) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue, Geographic Location [Line Items]
Sales	$ 8,189	$ 6,735
Concentration Risk, Percentage	100.00%	100.00%
United States
Revenue, Geographic Location [Line Items]
Sales	$ 6,972	$ 5,865
Concentration Risk, Percentage	85.00%	87.00%
United States | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 3,056	$ 2,950
Concentration Risk, Percentage	89.00%	92.00%
United States | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,129	$ 0
Concentration Risk, Percentage	82.00%	0.00%
United States | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,201	$ 2,220
Concentration Risk, Percentage	86.00%	85.00%
United States | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 586	$ 695
Concentration Risk, Percentage	74.00%	76.00%
Asia/Pacific
Revenue, Geographic Location [Line Items]
Sales	$ 468	$ 314
Concentration Risk, Percentage	6.00%	5.00%
Asia/Pacific | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 239	$ 129
Concentration Risk, Percentage	7.00%	4.00%
Asia/Pacific | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 45	$ 0
Concentration Risk, Percentage	3.00%	0.00%
Asia/Pacific | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 146	$ 153
Concentration Risk, Percentage	5.00%	6.00%
Asia/Pacific | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 38	$ 32
Concentration Risk, Percentage	4.00%	3.00%
All other
Revenue, Geographic Location [Line Items]
Sales	$ 749	$ 556
Concentration Risk, Percentage	9.00%	8.00%
All other | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 155	$ 142
Concentration Risk, Percentage	4.00%	4.00%
All other | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 202	$ 0
Concentration Risk, Percentage	15.00%	0.00%
All other | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 221	$ 226
Concentration Risk, Percentage	9.00%	9.00%
All other | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 171	$ 188
Concentration Risk, Percentage	22.00%	21.00%
Intersegment Eliminations [Member] | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 46	$ 59
Intersegment Eliminations [Member] | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	62	0
Intersegment Eliminations [Member] | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	318	284
Intersegment Eliminations [Member] | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	182	229
Operating Segments [Member] | Aerospace Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 3,496	$ 3,280
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Innovation Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,438	$ 0
Concentration Risk, Percentage	100.00%	0.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,886	$ 2,883
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Technology Services [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 977	$ 1,144
Concentration Risk, Percentage	100.00%	100.00%