Segment Information Intersegment Sales and Operating Income (Details 5) - USD ($) $ in Millions	3 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, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [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
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income	$ 1,136	$ 951	$ 946	$ 936	$ 943	$ 1,172	$ 817	$ 848	3,969	3,780	3,218
Intersegment sales
Segment Reporting Information [Line Items]
Sales									2,513	2,283	2,284
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									292	270	277
Intersegment sales | Aerospace Systems
Segment Reporting Information [Line Items]
Sales									204	197	295
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									23	23	33
Intersegment sales | Innovation Systems
Segment Reporting Information [Line Items]
Sales									331	127	0
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									14	1	0
Intersegment sales | Mission Systems
Segment Reporting Information [Line Items]
Sales									1,227	1,145	954
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									177	165	141
Intersegment sales | Technology Services
Segment Reporting Information [Line Items]
Sales									751	814	1,035
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									$ 78	$ 81	$ 103