9. STOCK- BASED COMPENSATION - Options outstanding by exercise price (Details) - $ / shares	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Options outstanding by exercise price
Exercise Price (in dollars per share)	$ 5.08	$ 5.16	$ 5.13	$ 4.46
Number of Shares Underlying Options Outstanding (in shares)	7,625,705
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.08
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 2 months 1 day
Options Exercisable, Number Vested and Exercisable (in shares)	5,246,088
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.02
$2.43 - $3.40
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)	$ 3.40
Number of Shares Underlying Options Outstanding (in shares)	895,204
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.17
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 22 days
Options Exercisable, Number Vested and Exercisable (in shares)	586,394
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.05
$3.43 - $4.00
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	3.43
Exercise Price, high end of range (in dollars per share)	$ 4.00
Number of Shares Underlying Options Outstanding (in shares)	1,118,969
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.81
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 1 month 6 days
Options Exercisable, Number Vested and Exercisable (in shares)	1,118,969
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.81
$4.17 - $4.81
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)	$ 4.81
Number of Shares Underlying Options Outstanding (in shares)	935,478
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.41
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 9 months
Options Exercisable, Number Vested and Exercisable (in shares)	670,261
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.33
$4.90 - $4.98
Options outstanding by exercise price
Exercise Price, low end of range (in dollars per share)	4.90
Exercise Price, high end of range (in dollars per share)	$ 4.98
Number of Shares Underlying Options Outstanding (in shares)	793,963
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.95
Options Outstanding, Weighted Average Remaining Contractual Life	7 years 11 months 1 day
Options Exercisable, Number Vested and Exercisable (in shares)	298,150
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.91
$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 5 months 27 days
Options Exercisable, Number Vested and Exercisable (in shares)	62,626
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.22
$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	7 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)	899,930
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.77
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 2 months 27 days
Options Exercisable, Number Vested and Exercisable (in shares)	568,526
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.80
$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)	808,219
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 6.48
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 29 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	5 years 9 months 4 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	4 years 9 months 29 days
Options Exercisable, Number Vested and Exercisable (in shares)	113,620
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 9.20