Fair Value of Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2017	Dec. 31, 2017	Dec. 13, 2017	Nov. 30, 2017	Feb. 29, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Payment for earnout amount	$ 2.0
Equity interest acquired		93.80%		93.80%
Convertible Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt instrument, interest rate		0.25%
Other Long-term Liabilities | ASC 815-10, Derivatives and Hedging
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity method Investment, noncurrent liabilities		$ 2.2	$ 2.2
EpiWorks | Upon Achievement of Financial and Operational Targets For Capacity Wafers Output and Gross Margin | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Business acquisitions, contingent consideration					$ 6.0
IPI | Upon Achievement of Financial And Transitional Objectives Relating to Finance Information Technology And Human Resources | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Business acquisitions, contingent consideration	$ 2.5