Business Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 28, 2018	Dec. 29, 2017	Dec. 28, 2018	Dec. 29, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 1,666	$ 1,535	$ 3,208	$ 2,945
Communication Systems
Disaggregation of Revenue [Line Items]
Revenue	540	492	1,009	898
Communication Systems | United States
Disaggregation of Revenue [Line Items]
Revenue	299	276	558	484
Communication Systems | International
Disaggregation of Revenue [Line Items]
Revenue	241	216	451	414
Electronic Systems
Disaggregation of Revenue [Line Items]
Revenue	617	582	1,206	1,123
Electronic Systems | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	508	463	986	885
Electronic Systems | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	109	119	220	238
Electronic Systems | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	399	410	793	808
Electronic Systems | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	218	172	413	315
Electronic Systems | United States
Disaggregation of Revenue [Line Items]
Revenue	486	464	964	890
Electronic Systems | International
Disaggregation of Revenue [Line Items]
Revenue	131	118	242	233
Space and Intelligence Systems
Disaggregation of Revenue [Line Items]
Revenue	513	462	1,001	928
Space and Intelligence Systems | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	188	120	360	243
Space and Intelligence Systems | Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	325	342	641	685
Space and Intelligence Systems | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	362	329	714	663
Space and Intelligence Systems | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	151	133	287	265
Space and Intelligence Systems | United States
Disaggregation of Revenue [Line Items]
Revenue	500	446	976	898
Space and Intelligence Systems | International
Disaggregation of Revenue [Line Items]
Revenue	$ 13	$ 16	$ 25	$ 30