Revenue - Revenue by Contract Type (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Revenue [Line Items]
Revenue	$ 9,761	$ 9,094	$ 28,577	$ 25,815
Aerospace
Revenue [Line Items]
Revenue	2,495	2,031	6,871	5,751
Combat Systems
Revenue [Line Items]
Revenue	1,740	1,523	5,035	4,497
Information Technology
Revenue [Line Items]
Revenue	2,071	2,307	6,398	5,887
Mission Systems
Revenue [Line Items]
Revenue	1,220	1,230	3,655	3,475
Marine Systems
Revenue [Line Items]
Revenue	2,235	2,003	6,618	6,205
Fixed-price
Revenue [Line Items]
Revenue	6,867	6,036	19,865	17,384
Fixed-price | Aerospace
Revenue [Line Items]
Revenue	2,306	1,807	6,271	5,171
Fixed-price | Combat Systems
Revenue [Line Items]
Revenue	1,501	1,309	4,344	3,892
Fixed-price | Information Technology
Revenue [Line Items]
Revenue	824	941	2,620	2,387
Fixed-price | Mission Systems
Revenue [Line Items]
Revenue	719	695	2,122	1,973
Fixed-price | Marine Systems
Revenue [Line Items]
Revenue	1,517	1,284	4,508	3,961
Cost-reimbursement
Revenue [Line Items]
Revenue	2,242	2,376	6,705	6,673
Cost-reimbursement | Aerospace
Revenue [Line Items]
Revenue	0	0	0	0
Cost-reimbursement | Combat Systems
Revenue [Line Items]
Revenue	230	204	662	580
Cost-reimbursement | Information Technology
Revenue [Line Items]
Revenue	838	955	2,537	2,462
Cost-reimbursement | Mission Systems
Revenue [Line Items]
Revenue	458	499	1,405	1,390
Cost-reimbursement | Marine Systems
Revenue [Line Items]
Revenue	716	718	2,101	2,241
Time-and-materials
Revenue [Line Items]
Revenue	652	682	2,007	1,758
Time-and-materials | Aerospace
Revenue [Line Items]
Revenue	189	224	600	580
Time-and-materials | Combat Systems
Revenue [Line Items]
Revenue	9	10	29	25
Time-and-materials | Information Technology
Revenue [Line Items]
Revenue	409	411	1,241	1,038
Time-and-materials | Mission Systems
Revenue [Line Items]
Revenue	43	36	128	112
Time-and-materials | Marine Systems
Revenue [Line Items]
Revenue	$ 2	$ 1	$ 9	$ 3