Sales and Marketing Support Accrual Activity (Detail) - Allowance for Promotions - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 117	$ 294
additions	416	611
usages	(433)	(593)
adjustments	(16)	(195)
Ending Balance	$ 84	$ 117

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- Definition

Amount of increase (decrease) in valuation and qualifying accounts and reserves from adjustment.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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- Definition

Amount of valuation and qualifying accounts and reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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- Definition

Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.

+ References

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- Definition

Amount of decrease in valuation and qualifying accounts and reserves.

+ References

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