Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Other Intangible Assets [Line Items]
Amortization expense recorded on intangible assets	$ 3.8	$ 3.2	$ 7.4	$ 6.4
Carrying amount of indefinite trade names acquired	14.1		$ 14.1
Technology and Patents
Goodwill And Other Intangible Assets [Line Items]
Remaining amortization period of patents and customer lists, in months			95 months
Technology and Patents | II-VI Compound Semiconductors Ltd
Goodwill And Other Intangible Assets [Line Items]
Identifiable intangibles assets recorded in connection with acquisitions	0.4		$ 0.4
Technology and Patents | Minimum
Goodwill And Other Intangible Assets [Line Items]
Amortization period of finite lived intangible assets, in months			60 months
Technology and Patents | Maximum
Goodwill And Other Intangible Assets [Line Items]
Amortization period of finite lived intangible assets, in months			240 months
Customer Lists
Goodwill And Other Intangible Assets [Line Items]
Remaining amortization period of patents and customer lists, in months			144 months
Customer Lists | II-VI Compound Semiconductors Ltd
Goodwill And Other Intangible Assets [Line Items]
Identifiable intangibles assets recorded in connection with acquisitions	$ 3.6		$ 3.6
Customer Lists | Minimum
Goodwill And Other Intangible Assets [Line Items]
Amortization period of finite lived intangible assets, in months			120 months
Customer Lists | Maximum
Goodwill And Other Intangible Assets [Line Items]
Amortization period of finite lived intangible assets, in months			240 months