Operating Segment, Geographic Information and Significant Customers - Customers Comprising Ten Percent or more Revenues (Detail) - Sales Revenue, Net	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Revenue, Major Customer [Line Items]
Concentration risk, percentage	11.00%	14.00%
Customer Concentration Risk
Revenue, Major Customer [Line Items]
Concentration risk, percentage	49.00%	40.00%
Customer Concentration Risk | Raytheon Company
Revenue, Major Customer [Line Items]
Concentration risk, percentage	21.00%	15.00%
Customer Concentration Risk | Lockheed Martin Corporation
Revenue, Major Customer [Line Items]
Concentration risk, percentage	18.00%	25.00%
Customer Concentration Risk | Northrop Grumman Corporation
Revenue, Major Customer [Line Items]
Concentration risk, percentage	10.00%