Segment Information - Summary of Financial Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Segment Reporting Information [Line Items]
Revenue	$ 9,261	$ 7,535
Operating earnings	1,014	1,008
Aerospace
Segment Reporting Information [Line Items]
Revenue	2,240	1,825
Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,636	1,440
Information Technology
Segment Reporting Information [Line Items]
Revenue	2,169	1,138
Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,158	1,098
Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,058	2,034
Operating Segments | Aerospace
Segment Reporting Information [Line Items]
Revenue	2,240	1,825
Operating earnings	328	346
Operating Segments | Combat Systems
Segment Reporting Information [Line Items]
Revenue	1,636	1,440
Operating earnings	206	224
Operating Segments | Information Technology
Segment Reporting Information [Line Items]
Revenue	2,169	1,138
Operating earnings	156	101
Operating Segments | Mission Systems
Segment Reporting Information [Line Items]
Revenue	1,158	1,098
Operating earnings	148	146
Operating Segments | Marine Systems
Segment Reporting Information [Line Items]
Revenue	2,058	2,034
Operating earnings	180	184
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0
Operating earnings	$ (4)	$ 7