Segment Information (Unaudited) Sales by Geographic Location (Details 4) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue, Geographic Location [Line Items]
Sales	$ 8,720	$ 9,083	$ 27,028	$ 26,587
Sales percentage	100.00%	100.00%	100.00%	100.00%
United States
Revenue, Geographic Location [Line Items]
Sales	$ 7,535	$ 7,840	$ 23,277	$ 22,748
Sales percentage	87.00%	86.00%	86.00%	86.00%
United States | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,317	$ 2,502	$ 7,381	$ 7,364
Sales percentage	87.00%	87.00%	86.00%	86.00%
United States | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 887	$ 1,361	$ 2,810	$ 4,121
Sales percentage	74.00%	82.00%	74.00%	81.00%
United States | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,775	$ 1,903	$ 5,540	$ 5,385
Sales percentage	81.00%	81.00%	81.00%	79.00%
United States | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,556	$ 2,074	$ 7,546	$ 5,878
Sales percentage	97.00%	96.00%	97.00%	96.00%
Asia/Pacific
Revenue, Geographic Location [Line Items]
Sales	$ 470	$ 447	$ 1,469	$ 1,422
Sales percentage	5.00%	5.00%	5.00%	5.00%
Asia/Pacific | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 239	$ 217	$ 722	$ 626
Sales percentage	9.00%	7.00%	9.00%	7.00%
Asia/Pacific | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 107	$ 103	$ 336	$ 292
Sales percentage	9.00%	6.00%	9.00%	6.00%
Asia/Pacific | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 114	$ 122	$ 372	$ 489
Sales percentage	5.00%	5.00%	5.00%	7.00%
Asia/Pacific | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 10	$ 5	$ 39	$ 15
Sales percentage	0.00%	0.00%	0.00%
Europe
Revenue, Geographic Location [Line Items]
Sales	$ 498	$ 545	$ 1,568	$ 1,539
Sales percentage	6.00%	6.00%	6.00%	6.00%
Europe | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 108	$ 129	$ 335	$ 445
Sales percentage	4.00%	5.00%	4.00%	5.00%
Europe | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 78	$ 73	$ 233	$ 213
Sales percentage	6.00%	4.00%	6.00%	4.00%
Europe | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 233	$ 253	$ 744	$ 669
Sales percentage	11.00%	11.00%	11.00%	10.00%
Europe | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 79	$ 90	$ 256	$ 212
Sales percentage	3.00%	4.00%	3.00%	4.00%
All other
Revenue, Geographic Location [Line Items]
Sales	$ 217	$ 251	$ 714	$ 878
Sales percentage	2.00%	3.00%	3.00%	3.00%
All other | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 13	$ 36	$ 53	$ 162
Sales percentage	0.00%	1.00%	1.00%	2.00%
All other | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 131	$ 131	$ 433	$ 458
Sales percentage	11.00%	8.00%	11.00%	9.00%
All other | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 70	$ 80	$ 222	$ 248
Sales percentage	3.00%	3.00%	3.00%	4.00%
All other | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 3	$ 4	$ 6	$ 10
Sales percentage	0.00%	0.00%	0.00%
Intersegment sales | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 48	$ 30	$ 137	85
Intersegment sales | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	206	191	586	542
Intersegment sales | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	244	193	735	553
Intersegment sales | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	33	25	103	79
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,725	$ 2,914	$ 8,628	$ 8,682
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,409	$ 1,859	$ 4,398	$ 5,626
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,436	$ 2,551	$ 7,613	$ 7,344
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,681	$ 2,198	$ 7,950	$ 6,194
Sales percentage	100.00%	100.00%	100.00%	100.00%