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Business Segments - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) segment MW	Dec. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable business segments | segment			2
Stock-based compensation expense	$ 883	$ 613	$ 2,115	$ 2,266
Restructuring charges	1	0	1,328	0
Change in fair value of contingent consideration	272	0	$ 71	0
Minimum
Segment Reporting Information [Line Items]
Megawatts of drive trains and power ratings | MW			2
Unallocated corporate expenses
Segment Reporting Information [Line Items]
Stock-based compensation expense	$ 900	$ 600	$ 2,100	$ 2,300
Restructuring charges			$ 1,300

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Power of wind turbines.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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