INFORMATION ON BUSINESS SEGMENTS - Income Statement Information For Each Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 26, 2021	Sep. 27, 2020
Net sales
Net sales	$ 16,028	$ 16,495	$ 49,315	$ 48,366
United States
Net sales
Net sales	11,883	11,707	36,078	36,150
Asia Pacific
Net sales
Net sales	1,366	1,573	4,468	3,894
Europe
Net sales
Net sales	1,381	1,900	4,916	4,741
Middle East
Net sales
Net sales	1,137	1,121	3,005	2,925
Other
Net sales
Net sales	261	194	848	656
U.S. Government
Net sales
Net sales	11,759	11,570	35,759	35,738
International
Net sales
Net sales	4,145	4,788	13,237	12,216
U.S. commercial and other
Net sales
Net sales	124	137	319	412
Fixed-price
Net sales
Net sales	9,967	9,934	30,228	28,703
Cost-reimbursable
Net sales
Net sales	6,061	6,561	19,087	19,663
Products
Net sales
Net sales	13,475	13,869	41,486	40,607
Services
Net sales
Net sales	2,553	2,626	7,829	7,759
Aeronautics
Net sales
Net sales	6,568	6,680	19,621	19,552
Aeronautics | United States
Net sales
Net sales	4,339	3,951	13,010	13,370
Aeronautics | Asia Pacific
Net sales
Net sales	890	1,099	2,697	2,447
Aeronautics | Europe
Net sales
Net sales	910	1,141	2,708	2,595
Aeronautics | Middle East
Net sales
Net sales	360	440	955	981
Aeronautics | Other
Net sales
Net sales	69	49	251	159
Aeronautics | U.S. Government
Net sales
Net sales	4,312	3,930	12,952	13,315
Aeronautics | International
Net sales
Net sales	2,229	2,729	6,611	6,182
Aeronautics | U.S. commercial and other
Net sales
Net sales	27	21	58	55
Aeronautics | Fixed-price
Net sales
Net sales	4,819	4,718	14,473	13,769
Aeronautics | Cost-reimbursable
Net sales
Net sales	1,749	1,962	5,148	5,783
Aeronautics | Products
Net sales
Net sales	5,573	5,742	16,635	16,671
Aeronautics | Services
Net sales
Net sales	995	938	2,986	2,881
MFC
Net sales
Net sales	2,781	2,971	8,474	8,391
MFC | United States
Net sales
Net sales	1,934	2,207	6,158	6,268
MFC | Asia Pacific
Net sales
Net sales	81	70	188	217
MFC | Europe
Net sales
Net sales	226	208	640	546
MFC | Middle East
Net sales
Net sales	527	475	1,452	1,324
MFC | Other
Net sales
Net sales	13	11	36	36
MFC | U.S. Government
Net sales
Net sales	1,938	2,206	6,155	6,259
MFC | International
Net sales
Net sales	847	764	2,316	2,123
MFC | U.S. commercial and other
Net sales
Net sales	(4)	1	3	9
MFC | Fixed-price
Net sales
Net sales	1,900	2,034	5,769	5,629
MFC | Cost-reimbursable
Net sales
Net sales	881	937	2,705	2,762
MFC | Products
Net sales
Net sales	2,429	2,614	7,410	7,311
MFC | Services
Net sales
Net sales	352	357	1,064	1,080
RMS
Net sales
Net sales	3,980	3,998	12,329	11,783
RMS | United States
Net sales
Net sales	2,933	3,084	8,945	9,003
RMS | Asia Pacific
Net sales
Net sales	409	383	1,593	1,165
RMS | Europe
Net sales
Net sales	213	191	637	528
RMS | Middle East
Net sales
Net sales	246	206	593	626
RMS | Other
Net sales
Net sales	179	134	561	461
RMS | U.S. Government
Net sales
Net sales	2,838	2,971	8,711	8,685
RMS | International
Net sales
Net sales	1,047	914	3,384	2,780
RMS | U.S. commercial and other
Net sales
Net sales	95	113	234	318
RMS | Fixed-price
Net sales
Net sales	2,617	2,666	8,096	7,787
RMS | Cost-reimbursable
Net sales
Net sales	1,363	1,332	4,233	3,996
RMS | Products
Net sales
Net sales	3,201	3,120	9,870	9,365
RMS | Services
Net sales
Net sales	779	878	2,459	2,418
Space
Net sales
Net sales	2,699	2,846	8,891	8,640
Space | United States
Net sales
Net sales	2,677	2,465	7,965	7,509
Space | Asia Pacific
Net sales
Net sales	(14)	21	(10)	65
Space | Europe
Net sales
Net sales	32	360	931	1,072
Space | Middle East
Net sales
Net sales	4	0	5	(6)
Space | Other
Net sales
Net sales	0	0	0	0
Space | U.S. Government
Net sales
Net sales	2,671	2,463	7,941	7,479
Space | International
Net sales
Net sales	22	381	926	1,131
Space | U.S. commercial and other
Net sales
Net sales	6	2	24	30
Space | Fixed-price
Net sales
Net sales	631	516	1,890	1,518
Space | Cost-reimbursable
Net sales
Net sales	2,068	2,330	7,001	7,122
Space | Products
Net sales
Net sales	2,272	2,393	7,571	7,260
Space | Services
Net sales
Net sales	$ 427	$ 453	$ 1,320	$ 1,380