Stock-Based Compensation - Stock Options & RSU (Details)	6 Months Ended
	Sep. 30, 2016 plan $ / shares shares
Employee Benefit Plans
Number of stock incentive plans | plan	1
Stock options
Number of Options
Options outstanding at the beginning of the period (in shares)	3,309,000
Granted (in shares)	70,000
Exercised (in shares)	(115,000)
Forfeited (in shares)	(18,000)
Expired (in shares)	(13,000)
Options outstanding at the end of the period (in shares)	3,233,000
Weighted Average Exercise Price Per Share
Options outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 2.07
Granted (in dollars per share) | $ / shares	3.61
Exercised (in dollars per share) | $ / shares	1.86
Forfeited (in dollars per share) | $ / shares	1.85
Expired (in dollars per share) | $ / shares	2.05
Options outstanding at the end of the period (in dollars per share) | $ / shares	$ 2.11
Restricted stock units
Weighted Average Exercise Price Per Share
Number of shares of common stock receivable upon vesting of each RSU	1
Number of Shares
RSUs outstanding at the beginning of the period (in shares)	173,000
Granted (in shares)	3,000
Vested (in shares)	(34,000)
Forfeited (in shares)	(5,000)
RSUs outstanding at the end of the period (in shares)	137,000
2007 Plan
Employee Benefit Plans
Authorized for future issuance under stock incentive plans (in shares)	870,000
Vested and expected to vest at the end of the period (in shares)	3,000,000