Segment Information (Unaudited) (Details 3) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue, Contract Type [Line Items]
Sales	$ 8,475	$ 8,085	$ 25,120	$ 21,939
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Cost-type [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,076	$ 3,958	$ 12,264	$ 11,201
Concentration Risk, Percentage	48.00%	49.00%	49.00%	51.00%
Cost-type [Member] | Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,995	$ 1,953	$ 5,976	$ 5,789
Concentration Risk, Percentage	59.00%	60.00%	59.00%	59.00%
Cost-type [Member] | Innovation Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 419	$ 373	$ 1,232	$ 472
Concentration Risk, Percentage	28.00%	27.00%	29.00%	27.00%
Cost-type [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,264	$ 1,259	$ 3,854	$ 3,745
Concentration Risk, Percentage	47.00%	48.00%	47.00%	48.00%
Cost-type [Member] | Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales	$ 398	$ 373	$ 1,202	$ 1,195
Concentration Risk, Percentage	46.00%	45.00%	47.00%	46.00%
Fixed-price [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,399	$ 4,127	$ 12,856	$ 10,738
Concentration Risk, Percentage	52.00%	51.00%	51.00%	49.00%
Fixed-price [Member] | Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,408	$ 1,287	$ 4,215	$ 3,958
Concentration Risk, Percentage	41.00%	40.00%	41.00%	41.00%
Fixed-price [Member] | Innovation Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,071	$ 1,005	$ 3,040	$ 1,293
Concentration Risk, Percentage	72.00%	73.00%	71.00%	73.00%
Fixed-price [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,444	$ 1,372	$ 4,268	$ 4,065
Concentration Risk, Percentage	53.00%	52.00%	53.00%	52.00%
Fixed-price [Member] | Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales	$ 476	$ 463	$ 1,333	$ 1,422
Concentration Risk, Percentage	54.00%	55.00%	53.00%	54.00%
Intersegment sales | Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 55	$ 42	$ 153	$ 152
Intersegment sales | Innovation Systems [Member]
Revenue, Contract Type [Line Items]
Sales	94	37	248	50
Intersegment sales | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	321	280	921	858
Intersegment sales | Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales	193	204	553	615
Operating Segments [Member] | Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 3,458	$ 3,282	$ 10,344	$ 9,899
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Innovation Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,584	$ 1,415	$ 4,520	$ 1,815
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 3,029	$ 2,911	$ 9,043	$ 8,668
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,067	$ 1,040	$ 3,088	$ 3,232
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%