Revenue - Revenue by Customer (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Revenue [Line Items]
Revenue	$ 9,555	$ 9,186	$ 18,816	$ 16,721
Aerospace
Revenue [Line Items]
Revenue	2,136	1,895	4,376	3,720
Combat Systems
Revenue [Line Items]
Revenue	1,659	1,534	3,295	2,974
Information Technology
Revenue [Line Items]
Revenue	2,158	2,442	4,327	3,580
Mission Systems
Revenue [Line Items]
Revenue	1,277	1,147	2,435	2,245
Marine Systems
Revenue [Line Items]
Revenue	2,325	2,168	4,383	4,202
U.S. Government - Department of Defense (DoD)
Revenue [Line Items]
Revenue	5,015	4,569	9,614	8,342
U.S. Government - Department of Defense (DoD) | Aerospace
Revenue [Line Items]
Revenue	52	89	175	130
U.S. Government - Department of Defense (DoD) | Combat Systems
Revenue [Line Items]
Revenue	910	660	1,703	1,267
U.S. Government - Department of Defense (DoD) | Information Technology
Revenue [Line Items]
Revenue	926	1,024	1,850	1,457
U.S. Government - Department of Defense (DoD) | Mission Systems
Revenue [Line Items]
Revenue	884	764	1,668	1,506
U.S. Government - Department of Defense (DoD) | Marine Systems
Revenue [Line Items]
Revenue	2,243	2,032	4,218	3,982
U.S. Government - Non Department of Defense (Non-DoD)
Revenue [Line Items]
Revenue	1,315	1,473	2,645	2,229
U.S. Government - Non Department of Defense (Non-DoD) | Aerospace
Revenue [Line Items]
Revenue	0	0	0	0
U.S. Government - Non Department of Defense (Non-DoD) | Combat Systems
Revenue [Line Items]
Revenue	3	3	6	4
U.S. Government - Non Department of Defense (Non-DoD) | Information Technology
Revenue [Line Items]
Revenue	1,178	1,339	2,370	1,976
U.S. Government - Non Department of Defense (Non-DoD) | Mission Systems
Revenue [Line Items]
Revenue	133	130	268	248
U.S. Government - Non Department of Defense (Non-DoD) | Marine Systems
Revenue [Line Items]
Revenue	1	1	1	1
U.S. Government - Foreign Military Sales (FMS)
Revenue [Line Items]
Revenue	167	162	319	291
U.S. Government - Foreign Military Sales (FMS) | Aerospace
Revenue [Line Items]
Revenue	14	19	29	35
U.S. Government - Foreign Military Sales (FMS) | Combat Systems
Revenue [Line Items]
Revenue	90	83	169	152
U.S. Government - Foreign Military Sales (FMS) | Information Technology
Revenue [Line Items]
Revenue	4	7	9	15
U.S. Government - Foreign Military Sales (FMS) | Mission Systems
Revenue [Line Items]
Revenue	12	14	21	21
U.S. Government - Foreign Military Sales (FMS) | Marine Systems
Revenue [Line Items]
Revenue	47	39	91	68
U.S. Government
Revenue [Line Items]
Revenue	6,497	6,204	12,578	10,862
U.S. Government | Aerospace
Revenue [Line Items]
Revenue	66	108	204	165
U.S. Government | Combat Systems
Revenue [Line Items]
Revenue	1,003	746	1,878	1,423
U.S. Government | Information Technology
Revenue [Line Items]
Revenue	2,108	2,370	4,229	3,448
U.S. Government | Mission Systems
Revenue [Line Items]
Revenue	1,029	908	1,957	1,775
U.S. Government | Marine Systems
Revenue [Line Items]
Revenue	2,291	2,072	4,310	4,051
U.S. Commercial
Revenue [Line Items]
Revenue	1,415	1,143	2,905	2,163
U.S. Commercial | Aerospace
Revenue [Line Items]
Revenue	1,242	917	2,571	1,759
U.S. Commercial | Combat Systems
Revenue [Line Items]
Revenue	59	58	109	116
U.S. Commercial | Information Technology
Revenue [Line Items]
Revenue	45	41	85	81
U.S. Commercial | Mission Systems
Revenue [Line Items]
Revenue	39	36	74	63
U.S. Commercial | Marine Systems
Revenue [Line Items]
Revenue	30	91	66	144
Non-U.S. Government
Revenue [Line Items]
Revenue	916	1,051	1,852	1,952
Non-U.S. Government | Aerospace
Revenue [Line Items]
Revenue	141	143	200	153
Non-U.S. Government | Combat Systems
Revenue [Line Items]
Revenue	587	712	1,288	1,409
Non-U.S. Government | Information Technology
Revenue [Line Items]
Revenue	5	31	13	51
Non-U.S. Government | Mission Systems
Revenue [Line Items]
Revenue	181	161	347	333
Non-U.S. Government | Marine Systems
Revenue [Line Items]
Revenue	2	4	4	6
Non-U.S. Commercial
Revenue [Line Items]
Revenue	727	788	1,481	1,744
Non-U.S. Commercial | Aerospace
Revenue [Line Items]
Revenue	687	727	1,401	1,643
Non-U.S. Commercial | Combat Systems
Revenue [Line Items]
Revenue	10	18	20	26
Non-U.S. Commercial | Information Technology
Revenue [Line Items]
Revenue	0	0	0	0
Non-U.S. Commercial | Mission Systems
Revenue [Line Items]
Revenue	28	42	57	74
Non-U.S. Commercial | Marine Systems
Revenue [Line Items]
Revenue	$ 2	$ 1	$ 3	$ 1