Revenue - Revenue by Contract Type (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Revenue [Line Items]
Revenue	$ 9,261	$ 7,535
Aerospace
Revenue [Line Items]
Revenue	2,240	1,825
Combat Systems
Revenue [Line Items]
Revenue	1,636	1,440
Information Technology
Revenue [Line Items]
Revenue	2,169	1,138
Mission Systems
Revenue [Line Items]
Revenue	1,158	1,098
Marine Systems
Revenue [Line Items]
Revenue	2,058	2,034
Fixed-price
Revenue [Line Items]
Revenue	6,444	5,233
Fixed-price | Aerospace
Revenue [Line Items]
Revenue	2,040	1,668
Fixed-price | Combat Systems
Revenue [Line Items]
Revenue	1,416	1,253
Fixed-price | Information Technology
Revenue [Line Items]
Revenue	921	387
Fixed-price | Mission Systems
Revenue [Line Items]
Revenue	651	620
Fixed-price | Marine Systems
Revenue [Line Items]
Revenue	1,416	1,305
Cost-reimbursement
Revenue [Line Items]
Revenue	2,155	1,924
Cost-reimbursement | Aerospace
Revenue [Line Items]
Revenue	0	0
Cost-reimbursement | Combat Systems
Revenue [Line Items]
Revenue	211	179
Cost-reimbursement | Information Technology
Revenue [Line Items]
Revenue	841	577
Cost-reimbursement | Mission Systems
Revenue [Line Items]
Revenue	463	440
Cost-reimbursement | Marine Systems
Revenue [Line Items]
Revenue	640	728
Time-and-materials
Revenue [Line Items]
Revenue	662	378
Time-and-materials | Aerospace
Revenue [Line Items]
Revenue	200	157
Time-and-materials | Combat Systems
Revenue [Line Items]
Revenue	9	8
Time-and-materials | Information Technology
Revenue [Line Items]
Revenue	407	174
Time-and-materials | Mission Systems
Revenue [Line Items]
Revenue	44	38
Time-and-materials | Marine Systems
Revenue [Line Items]
Revenue	$ 2	$ 1