Revenue (Revenue by Contract Type) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue, Major Customer [Line Items]
Revenue	$ 39,350	$ 36,193	$ 30,973
Aerospace
Revenue, Major Customer [Line Items]
Revenue	9,801	8,455	8,129
Combat Systems
Revenue, Major Customer [Line Items]
Revenue	7,007	6,241	5,949
Information Technology
Revenue, Major Customer [Line Items]
Revenue	8,422	8,269	4,410
Mission Systems
Revenue, Major Customer [Line Items]
Revenue	4,937	4,726	4,481
Marine Systems
Revenue, Major Customer [Line Items]
Revenue	9,183	8,502	8,004
Fixed-price
Revenue, Major Customer [Line Items]
Revenue	27,673	24,606	21,320
Fixed-price | Aerospace
Revenue, Major Customer [Line Items]
Revenue	8,949	7,600	7,479
Fixed-price | Combat Systems
Revenue, Major Customer [Line Items]
Revenue	6,049	5,406	5,090
Fixed-price | Information Technology
Revenue, Major Customer [Line Items]
Revenue	3,436	3,396	1,465
Fixed-price | Mission Systems
Revenue, Major Customer [Line Items]
Revenue	2,908	2,711	2,478
Fixed-price | Marine Systems
Revenue, Major Customer [Line Items]
Revenue	6,331	5,493	4,808
Cost-reimbursement
Revenue, Major Customer [Line Items]
Revenue	8,996	9,087	8,152
Cost-reimbursement | Aerospace
Revenue, Major Customer [Line Items]
Revenue	0	0	0
Cost-reimbursement | Combat Systems
Revenue, Major Customer [Line Items]
Revenue	894	800	823
Cost-reimbursement | Information Technology
Revenue, Major Customer [Line Items]
Revenue	3,401	3,422	2,305
Cost-reimbursement | Mission Systems
Revenue, Major Customer [Line Items]
Revenue	1,862	1,861	1,838
Cost-reimbursement | Marine Systems
Revenue, Major Customer [Line Items]
Revenue	2,839	3,004	3,186
Time-and-materials
Revenue, Major Customer [Line Items]
Revenue	2,681	2,500	1,501
Time-and-materials | Aerospace
Revenue, Major Customer [Line Items]
Revenue	852	855	650
Time-and-materials | Combat Systems
Revenue, Major Customer [Line Items]
Revenue	64	35	36
Time-and-materials | Information Technology
Revenue, Major Customer [Line Items]
Revenue	1,585	1,451	640
Time-and-materials | Mission Systems
Revenue, Major Customer [Line Items]
Revenue	167	154	165
Time-and-materials | Marine Systems
Revenue, Major Customer [Line Items]
Revenue	$ 13	$ 5	$ 10