| Description of Stock Plans - Stock Compensation Expense (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
|---|---|---|---|
| Mar. 31, 2017 | Mar. 31, 2016 | Mar. 31, 2015 | |
| Deferred Compensation Arrangement With Individual Share Based Payments [Line Items] | |||
| Allocated Stock compensation expense | $ 4,156 | $ 5,963 | $ 6,340 | 
| Product development | |||
| Deferred Compensation Arrangement With Individual Share Based Payments [Line Items] | |||
| Allocated Stock compensation expense | 0 | 0 | 0 | 
| Sales and marketing | |||
| Deferred Compensation Arrangement With Individual Share Based Payments [Line Items] | |||
| Allocated Stock compensation expense | 0 | 0 | 0 | 
| General and administrative | |||
| Deferred Compensation Arrangement With Individual Share Based Payments [Line Items] | |||
| Allocated Stock compensation expense | $ 4,156 | $ 5,963 | $ 6,340 | 
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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