8. STOCK- BASED COMPENSATION - Stock options activities (Details)	6 Months Ended
	Sep. 30, 2016 USD ($) $ / shares shares
STOCK- BASED COMPENSATION
Shares available for grant, Beginning	6,432,063
Options reserved (in shares)	1,085,818
Terminated plan (in shares)	(705,699)
Granted (in shares)	(826,983)
Forfeited (in shares)	14,801
Shares available for grant, Ending	6,000,000
Number of Shares Underlying Options Outstanding
Balance at the beginning of the period (in shares)	7,625,705
Granted (in shares)	826,983
Exercised (in shares)	(86,700)
Forfeited (in shares)	(177,601)
Balance at the end of the period (in shares)	8,188,387
Options vested and exercisable (in shares)	5,361,750
Options vested and expected to vest (in shares)	8,132,488
Weighted Average Remaining Contractual Life
Options vested and exercisable	3 years 6 months 18 days
Options vested and expected to vest	5 years 3 months 4 days
Weighted Average Exercise Price
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 5.08
Granted (in dollars per share) | $ / shares	4.72
Exercised (in dollars per share) | $ / shares	3.60
Forfeited (in dollars per share) | $ / shares	5.68
Balance at the end of the period (in dollars per share) | $ / shares	5.04
Options vested and exercisable (in dollars per share) | $ / shares	5.04
Options vested and expected to vest (in dollars per share) | $ / shares	$ 5.04
Intrinsic Value
Exercised (in dollars) | $	$ 96,209
Options vested and exercisable (in dollars) | $	2,205,257
Options vested and expected to vest (in dollars) | $	$ 2,809,868