Segment Information Sales by Contract Type (Details 3) - 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, Contract Type [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%
Operating Segments [Member] | Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales										$ 13,862	$ 13,096	$ 12,131
Concentration Risk, Percentage										100.00%	100.00%	100.00%
Operating Segments [Member] | Innovation Systems
Revenue, Contract Type [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, Contract Type [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, Contract Type [Line Items]
Sales										$ 4,110	$ 4,297	$ 4,687
Concentration Risk, Percentage										100.00%	100.00%	100.00%
Cost-type
Revenue, Contract Type [Line Items]
Sales										$ 16,479	$ 15,004	$ 14,197
Concentration Risk, Percentage										49.00%	50.00%	55.00%
Cost-type | Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales										$ 8,049	$ 7,634	$ 7,193
Concentration Risk, Percentage										59.00%	59.00%	61.00%
Cost-type | Innovation Systems
Revenue, Contract Type [Line Items]
Sales										$ 1,699	$ 843	$ 0
Concentration Risk, Percentage										29.00%	27.00%	0.00%
Cost-type | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales										$ 5,164	$ 4,939	$ 5,311
Concentration Risk, Percentage										47.00%	47.00%	51.00%
Cost-type | Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales										$ 1,567	$ 1,588	$ 1,693
Concentration Risk, Percentage										47.00%	46.00%	46.00%
Fixed-price
Revenue, Contract Type [Line Items]
Sales										$ 17,362	$ 15,091	$ 11,807
Concentration Risk, Percentage										51.00%	50.00%	45.00%
Fixed-price | Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales										$ 5,609	$ 5,265	$ 4,643
Concentration Risk, Percentage										41.00%	41.00%	39.00%
Fixed-price | Innovation Systems
Revenue, Contract Type [Line Items]
Sales										$ 4,089	$ 2,306	$ 0
Concentration Risk, Percentage										71.00%	73.00%	0.00%
Fixed-price | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales										$ 5,872	$ 5,625	$ 5,205
Concentration Risk, Percentage										53.00%	53.00%	49.00%
Fixed-price | Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales										$ 1,792	$ 1,895	$ 1,959
Concentration Risk, Percentage										53.00%	54.00%	54.00%
Intersegment Sales [Member] | Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales										$ 204	$ 197	$ 295
Intersegment Sales [Member] | Innovation Systems
Revenue, Contract Type [Line Items]
Sales										331	127	0
Intersegment Sales [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales										1,227	1,145	954
Intersegment Sales [Member] | Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales										$ 751	$ 814	$ 1,035