Operating Segment, Geographic Information and Significant Customers - Programs Comprising Ten Percent or more of Company's Revenue (Detail) - Sales Revenue, Net	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Concentration risk, percentage	11.00%	0.00%	11.00%	0.00%
Program Concentration Risk [Member] | F-35 Program [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	11.00%		11.00%
Customer Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage	38.00%	49.00%	33.00%	49.00%
Raytheon Company | Customer Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage	25.00%	17.00%	22.00%	19.00%