Operating Segment, Geographic Information and Significant Customers - Net Revenue by End Application (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Revenue from External Customer [Line Items]
Net revenues	$ 152,867	$ 116,336	$ 117,912	$ 106,069	$ 115,608	$ 107,317	$ 98,014	$ 87,649	$ 493,184	$ 408,588	$ 270,154
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)									(596)	286
Radar End User Applications
Revenue from External Customer [Line Items]
Net revenues									159,737	150,441	140,289
Electronic Warfare End User Applications
Revenue from External Customer [Line Items]
Net revenues									114,801	106,446	72,118
Other Sensor And Effector Applications [Member]
Revenue from External Customer [Line Items]
Net revenues									48,088	27,719	12,494
Total Sensor And Effector Applications [Member]
Revenue from External Customer [Line Items]
Net revenues									322,626	284,606	224,901
C4I Applications [Member]
Revenue from External Customer [Line Items]
Net revenues									87,414	31,679	3,472
Other End User Applications
Revenue from External Customer [Line Items]
Net revenues									$ 83,144	$ 92,303	$ 41,781