Segment Information Sales by Customer Type (Details 2) - USD ($) $ in Millions	3 Months Ended								7 Months Ended	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue, Major Customer [Line Items]
Sales	$ 8,721	$ 8,475	$ 8,456	$ 8,189	$ 8,156	$ 8,085	$ 7,119	$ 6,735		$ 33,841	$ 30,095	$ 26,004
Concentration Risk, Percentage										100.00%	100.00%	100.00%
US Government
Revenue, Major Customer [Line Items]
Sales										$ 27,934	$ 24,796	$ 21,969
Concentration Risk, Percentage										83.00%	82.00%	85.00%
US Government | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 12,044	$ 11,380	$ 10,521
Concentration Risk, Percentage										87.00%	87.00%	87.00%
US Government | Innovation Systems
Revenue, Major Customer [Line Items]
Sales										$ 4,419	$ 2,241	$ 0
Concentration Risk, Percentage										72.00%	68.00%	0.00%
US Government | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 9,079	$ 8,803	$ 8,876
Concentration Risk, Percentage										74.00%	75.00%	77.00%
US Government | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales										$ 2,392	$ 2,372	$ 2,572
Concentration Risk, Percentage										58.00%	55.00%	55.00%
International
Revenue, Major Customer [Line Items]
Sales										$ 5,154	$ 4,434	$ 3,452
Concentration Risk, Percentage										15.00%	15.00%	13.00%
International | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 1,508	$ 1,371	$ 1,160
Concentration Risk, Percentage										11.00%	10.00%	10.00%
International | Innovation Systems
Revenue, Major Customer [Line Items]
Sales										$ 960	$ 615	$ 0
Concentration Risk, Percentage										16.00%	19.00%	0.00%
International | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 1,840	$ 1,647	$ 1,540
Concentration Risk, Percentage										15.00%	14.00%	14.00%
International | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales										$ 846	$ 801	$ 752
Concentration Risk, Percentage										21.00%	19.00%	16.00%
Other Customers
Revenue, Major Customer [Line Items]
Sales										$ 753	$ 865	$ 583
Concentration Risk, Percentage										2.00%	3.00%	2.00%
Other Customers | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 106	$ 148	$ 155
Concentration Risk, Percentage										1.00%	1.00%	1.00%
Other Customers | Innovation Systems
Revenue, Major Customer [Line Items]
Sales										$ 409	$ 293	$ 0
Concentration Risk, Percentage										7.00%	9.00%	0.00%
Other Customers | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 117	$ 114	$ 100
Concentration Risk, Percentage										1.00%	1.00%	1.00%
Other Customers | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales										$ 121	$ 310	$ 328
Concentration Risk, Percentage										3.00%	7.00%	7.00%
Intersegment Sales [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 204	$ 197	$ 295
Concentration Risk, Percentage										1.00%	2.00%	2.00%
Intersegment Sales [Member] | Innovation Systems
Revenue, Major Customer [Line Items]
Sales										$ 331	$ 127	$ 0
Concentration Risk, Percentage										5.00%	4.00%	0.00%
Intersegment Sales [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 1,227	$ 1,145	$ 954
Concentration Risk, Percentage										10.00%	10.00%	8.00%
Intersegment Sales [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales										$ 751	$ 814	$ 1,035
Concentration Risk, Percentage										18.00%	19.00%	22.00%
Operating Segments [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 13,862	$ 13,096	$ 12,131
Concentration Risk, Percentage										100.00%	100.00%	100.00%
Operating Segments [Member] | Innovation Systems
Revenue, Major Customer [Line Items]
Sales									$ 3,300	$ 6,119	$ 3,276	$ 0
Concentration Risk, Percentage										100.00%	100.00%	0.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales										$ 12,263	$ 11,709	$ 11,470
Concentration Risk, Percentage										100.00%	100.00%	100.00%
Operating Segments [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales										$ 4,110	$ 4,297	$ 4,687
Concentration Risk, Percentage										100.00%	100.00%	100.00%