Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	3 Months Ended
	Sep. 30, 2018 USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 497,442
Ending Balance	520,589
SMP
Goodwill [Roll Forward]
Beginning Balance	119,560
Ending Balance	119,560
AMS
Goodwill [Roll Forward]
Beginning Balance	218,147
Ending Balance	218,147
MDS
Goodwill [Roll Forward]
Beginning Balance	159,735
Ending Balance	182,882
Themis
Goodwill [Roll Forward]
Goodwill arising from acquisitions	(700)
Themis | SMP
Goodwill [Roll Forward]
Goodwill arising from acquisitions	0
Themis | AMS
Goodwill [Roll Forward]
Goodwill arising from acquisitions	0
Themis | MDS
Goodwill [Roll Forward]
Goodwill arising from acquisitions	(700)
Germane Systems
Goodwill [Roll Forward]
Goodwill arising from acquisitions	23,847
Germane Systems | MDS
Goodwill [Roll Forward]
Goodwill arising from acquisitions	$ 23,847