Business Segment Reporting (Segment Operating Performance) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Sales, net	$ 7,842,000,000	$ 7,446,000,000	$ 7,159,000,000	$ 6,729,000,000	$ 7,360,000,000	$ 6,806,000,000	$ 6,625,000,000	$ 6,267,000,000	$ 29,176,000,000	$ 27,058,000,000	$ 25,348,000,000
Operating income									4,774,000,000	4,538,000,000	4,231,000,000
Non-cash gain on revaluation of investment in equity securities of non-publicly traded company, reclassified from segment operating income to other (income) expense, net									14,000,000	0	0
Net expenses related to LTAMDS included in corporate operating income									13,000,000	0	0
Integrated Defense Systems
Segment Reporting Information [Line Items]
Sales, net									6,840,000,000	6,115,000,000	5,740,000,000
Intelligence, Information and Services
Segment Reporting Information [Line Items]
Sales, net									6,451,000,000	6,056,000,000	5,511,000,000
Missile Systems
Segment Reporting Information [Line Items]
Sales, net									8,516,000,000	8,137,000,000	7,655,000,000
Space and Airborne Systems
Segment Reporting Information [Line Items]
Sales, net									6,741,000,000	6,152,000,000	5,890,000,000
Forcepoint
Segment Reporting Information [Line Items]
Sales, net									628,000,000	598,000,000	552,000,000
Acquisition Accounting Adjustment [Member]
Segment Reporting Information [Line Items]
Sales, net									0	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Sales, net									29,177,000,000	27,068,000,000	25,383,000,000
Operating income									3,543,000,000	3,253,000,000	3,147,000,000
Operating Segments [Member] | Integrated Defense Systems
Segment Reporting Information [Line Items]
Sales, net									6,927,000,000	6,180,000,000	5,804,000,000
Operating income									1,111,000,000	1,023,000,000	935,000,000
Operating Segments [Member] | Intelligence, Information and Services
Segment Reporting Information [Line Items]
Sales, net									7,151,000,000	6,722,000,000	6,177,000,000
Operating income									658,000,000	538,000,000	455,000,000
Operating Segments [Member] | Missile Systems
Segment Reporting Information [Line Items]
Sales, net									8,726,000,000	8,298,000,000	7,787,000,000
Operating income									959,000,000	973,000,000	1,010,000,000
Operating Segments [Member] | Space and Airborne Systems
Segment Reporting Information [Line Items]
Sales, net									7,427,000,000	6,748,000,000	6,430,000,000
Operating income									991,000,000	884,000,000	862,000,000
Operating Segments [Member] | Forcepoint
Segment Reporting Information [Line Items]
Sales, net									658,000,000	634,000,000	608,000,000
Operating income									8,000,000	5,000,000	33,000,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales, net									(1,712,000,000)	(1,514,000,000)	(1,423,000,000)
Operating income									(184,000,000)	(170,000,000)	(148,000,000)
Intersegment Eliminations [Member] | Integrated Defense Systems
Segment Reporting Information [Line Items]
Sales, net									(87,000,000)	(65,000,000)	(64,000,000)
Operating income									(8,000,000)	(6,000,000)	(5,000,000)
Intersegment Eliminations [Member] | Intelligence, Information and Services
Segment Reporting Information [Line Items]
Sales, net									(700,000,000)	(666,000,000)	(666,000,000)
Operating income									(68,000,000)	(68,000,000)	(64,000,000)
Intersegment Eliminations [Member] | Missile Systems
Segment Reporting Information [Line Items]
Sales, net									(210,000,000)	(161,000,000)	(132,000,000)
Operating income									(20,000,000)	(15,000,000)	(13,000,000)
Intersegment Eliminations [Member] | Space and Airborne Systems
Segment Reporting Information [Line Items]
Sales, net									(686,000,000)	(596,000,000)	(540,000,000)
Operating income									(67,000,000)	(60,000,000)	(51,000,000)
Intersegment Eliminations [Member] | Forcepoint
Segment Reporting Information [Line Items]
Sales, net									(29,000,000)	(26,000,000)	(21,000,000)
Operating income									(21,000,000)	(21,000,000)	(15,000,000)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Sales, net									(1,713,000,000)	(1,524,000,000)	(1,458,000,000)
Segment Reconciling Items [Member] | Integrated Defense Systems
Segment Reporting Information [Line Items]
Sales, net									0	0	0
Segment Reconciling Items [Member] | Intelligence, Information and Services
Segment Reporting Information [Line Items]
Sales, net									0	0	0
Segment Reconciling Items [Member] | Missile Systems
Segment Reporting Information [Line Items]
Sales, net									0	0	0
Segment Reconciling Items [Member] | Space and Airborne Systems
Segment Reporting Information [Line Items]
Sales, net									0	0	0
Segment Reconciling Items [Member] | Forcepoint
Segment Reporting Information [Line Items]
Sales, net									(1,000,000)	(10,000,000)	(35,000,000)
Segment Reconciling Items [Member] | Acquisition Accounting Adjustment [Member]
Segment Reporting Information [Line Items]
Sales, net									(1,000,000)	(10,000,000)	(35,000,000)
Operating income									(112,000,000)	(126,000,000)	(160,000,000)
Segment Reconciling Items [Member] | FAS/CAS Operating Adjustment [Member]
Segment Reporting Information [Line Items]
Operating income									1,454,000,000	1,428,000,000	1,303,000,000
Corporate [Member]
Segment Reporting Information [Line Items]
Sales, net									0	0	0
Operating income									$ (111,000,000)	$ (17,000,000)	$ (59,000,000)