Share Based Awards - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
Dec. 31, 2017	Mar. 31, 2017
Number of Shares
Outstanding, April 1, 2017	2,885,415
Granted	1,479,000
Exercised	(216,405)
Forfeited/Canceled	(324,375)
Outstanding, December 31, 2017	3,823,635	2,885,415
Vested and expected to vest, December 31, 2017	3,401,964
Exercisable, December 31, 2017	923,480
Weighted- Average Exercise Price per Share
Outstanding, April 1, 2017 (in dollars per share)	$ 15.41
Granted (in dollars per share)	14.56
Exercised (in dollars per share)	16.62
Forfeited/Canceled (in dollars per share)	17.93
Outstanding, September 30, 2017 (in dollars per share)	15.73	$ 15.41
Vested and expected to vest, September 30, 2017 (in dollars per share)	15.90
Exercisable, September 30, 2017 (in dollars per share)	$ 19.96
Weighted- Average Remaining Contractual Life (years)
Outstanding	6 years 3 months 18 days	6 years 2 months 12 days
Granted	7 years 9 months 18 days
Exercised	6 years
Forfeited/Canceled	4 years 8 months 12 days
Vested and expected to vest, December 31, 2017	6 years 3 months 18 days
Exercisable, December 31, 2017	4 years 4 months 24 days
Aggregate Intrinsic Value
Outstanding, April 1, 2017	$ 3,150
Exercised	119
Outstanding, December 31, 2017	733	$ 3,150
Vested and expected to vest, December 31, 2017	654
Exercisable, December 31, 2017	$ 190

Share-based compensation arrangement by share-based payment award options aggregate intrinsic value rollforward.

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Share based compensation arrangement by share based payment award options forfeiture weighted average remaining contractual term.

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Share based compensation arrangement by share based payment award options granted weighted average remaining contractual term.

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Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Remaining Contractual Life [Roll Forward]

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest exercisable options that may be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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