Stock-Based Compensation - Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2016	Jun. 30, 2015
Summary of Stock-Based Compensation Expense of Stock Options and Restricted Stock Units
Stock-based compensation expense	$ 8,174	$ 6,104
Stock-based compensation capitalized to inventory	(9)	(12)
Total	8,165	6,092
Cost of Revenues
Summary of Stock-Based Compensation Expense of Stock Options and Restricted Stock Units
Stock-based compensation expense	167	105
Research and Development Expense
Summary of Stock-Based Compensation Expense of Stock Options and Restricted Stock Units
Stock-based compensation expense	5,993	4,060
Selling, General and Administrative
Summary of Stock-Based Compensation Expense of Stock Options and Restricted Stock Units
Stock-based compensation expense	2,014	1,939
Outstanding stock options
Summary of Stock-Based Compensation Expense of Stock Options and Restricted Stock Units
Stock-based compensation expense	327	207
Outstanding RSUs
Summary of Stock-Based Compensation Expense of Stock Options and Restricted Stock Units
Stock-based compensation expense	$ 7,847	$ 5,897

Stock based compensation expenses related to stock options and restricted stock units.

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section F

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(ii)
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Amount of capitalized and expensed compensation cost from equity-based compensation arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
-Subparagraph (h)(1)
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