7. STOCK- BASED COMPENSATION - Options outstanding by exercise price (Details) - $ / shares	9 Months Ended
	Dec. 31, 2015	Mar. 31, 2015
Options outstanding by exercise price
Exercise Price (in dollars per share)	$ 5.15	$ 5.16
Number of Shares Underlying Options Outstanding (in shares)	7,338,645
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.15
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 3 months
Options Exercisable, Number Vested and Exercisable (in shares)	4,976,550
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.05
$2.43 - $3.43
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	2.43
Exercise Price, high end of range (in dollars per share)	$ 3.43
Number of Shares Underlying Options Outstanding (in shares)	892,584
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.18
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 1 month 6 days
Options Exercisable, Number Vested and Exercisable (in shares)	892,584
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.18
$3.75 - $4.00
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	3.75
Exercise Price, high end of range (in dollars per share)	$ 4.00
Number of Shares Underlying Options Outstanding (in shares)	812,779
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.96
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 2 months 16 days
Options Exercisable, Number Vested and Exercisable (in shares)	812,779
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.96
$4.17 - $4.68
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	4.17
Exercise Price, high end of range (in dollars per share)	$ 4.68
Number of Shares Underlying Options Outstanding (in shares)	747,515
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.30
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 11 months 9 days
Options Exercisable, Number Vested and Exercisable (in shares)	357,926
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.30
$4.81 - $4.98
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	4.81
Exercise Price, high end of range (in dollars per share)	$ 4.98
Number of Shares Underlying Options Outstanding (in shares)	997,676
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.92
Options Outstanding, Weighted Average Remaining Contractual Life	7 years 10 months 17 days
Options Exercisable, Number Vested and Exercisable (in shares)	389,871
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.88
$5.13 - $5.34
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	5.13
Exercise Price, high end of range (in dollars per share)	$ 5.34
Number of Shares Underlying Options Outstanding (in shares)	625,513
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.23
Options Outstanding, Weighted Average Remaining Contractual Life	8 years 8 months 27 days
Options Exercisable, Number Vested and Exercisable (in shares)	49,980
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.19
$5.50
Options outstanding by exercise price
Exercise Price (in dollars per share)	$ 5.50
Number of Shares Underlying Options Outstanding (in shares)	783,433
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.50
Options Outstanding, Weighted Average Remaining Contractual Life	10 months 17 days
Options Exercisable, Number Vested and Exercisable (in shares)	783,433
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.50
$5.59 - $6.00
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	5.59
Exercise Price, high end of range (in dollars per share)	$ 6.00
Number of Shares Underlying Options Outstanding (in shares)	901,930
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.77
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 6 months 11 days
Options Exercisable, Number Vested and Exercisable (in shares)	532,248
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.81
$6.28 - $6.63
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	6.28
Exercise Price, high end of range (in dollars per share)	$ 6.63
Number of Shares Underlying Options Outstanding (in shares)	812,219
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 6.48
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 4 months 10 days
Options Exercisable, Number Vested and Exercisable (in shares)	645,440
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 6.47
$6.82 - $7.00
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	6.82
Exercise Price, high end of range (in dollars per share)	$ 7.00
Number of Shares Underlying Options Outstanding (in shares)	651,376
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 6.90
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 22 days
Options Exercisable, Number Vested and Exercisable (in shares)	398,669
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 6.92
$9.20
Options outstanding by exercise price
Exercise Price (in dollars per share)	$ 9.20
Number of Shares Underlying Options Outstanding (in shares)	113,620
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 9.20
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 26 days
Options Exercisable, Number Vested and Exercisable (in shares)	113,620
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 9.20