Revenue - Revenue by Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Revenue [Line Items]
Revenue	$ 9,431	$ 9,761	$ 27,444	$ 28,577
Aerospace
Revenue [Line Items]
Revenue	1,975	2,495	5,640	6,871
Aerospace | Aircraft manufacturing and completions
Revenue [Line Items]
Revenue	1,546	1,972	4,303	5,304
Aerospace | Aircraft services
Revenue [Line Items]
Revenue	429	523	1,337	1,567
Combat Systems
Revenue [Line Items]
Revenue	1,801	1,740	5,263	5,035
Combat Systems | Military vehicles
Revenue [Line Items]
Revenue	1,179	1,137	3,428	3,361
Combat Systems | Weapons systems, armament and munitions
Revenue [Line Items]
Revenue	496	474	1,444	1,336
Combat Systems | Engineering and other services
Revenue [Line Items]
Revenue	126	129	391	338
Information Technology
Revenue [Line Items]
Revenue	2,029	2,071	5,901	6,398
Information Technology | IT services
Revenue [Line Items]
Revenue	2,029	2,071	5,901	6,398
Mission Systems
Revenue [Line Items]
Revenue	1,221	1,220	3,518	3,655
Mission Systems | C4ISR solutions
Revenue [Line Items]
Revenue	1,221	1,220	3,518	3,655
Marine Systems
Revenue [Line Items]
Revenue	2,405	2,235	7,122	6,618
Marine Systems | Nuclear-powered submarines
Revenue [Line Items]
Revenue	1,704	1,567	4,972	4,482
Marine Systems | Surface ships
Revenue [Line Items]
Revenue	461	402	1,433	1,376
Marine Systems | Repair and other services
Revenue [Line Items]
Revenue	$ 240	$ 266	$ 717	$ 760