7. STOCK- BASED COMPENSATION (Details) (USD $)	3 Months Ended
	Jun. 30, 2014
Stock-Based Compensation
Shares available for grant, Beginning	5,585,500
Options reserved (in shares)	1,378,074
Granted (in shares)	(53,930)
Forfeited (in shares)	1,875
Shares available for grant, Ending	6,911,519
Number of Shares Underlying Options Outstanding
Balance at the beginning of the period (in shares)	6,143,980
Granted (in shares)	53,930
Exercised (in shares)	(23,500)
Forfeited (in shares)	(1,875)
Balance at the end of the period (in shares)	6,172,535
Options vested and exercisable (in shares)	4,085,844
Options vested and expected to vest (in shares)	6,131,192
Weighted Average Remaining Contractual Life
Options vested and exercisable (in dollars per share)	4 years 6 months 15 days
Options vested and expected to vest (in dollars per share)	5 years 9 months
Weighted Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$ 5.13
Granted (in dollars per share)	$ 5.75
Exercised (in dollars per share)	$ 3.49
Forfeited (in dollars per share)	$ 6.08
Balance at the end of the period (in dollars per share)	$ 5.14
Options vested and exercisable (in dollars per share)	$ 4.75
Options vested and expected to vest (in dollars per share)	$ 5.14
Intrinsic Value
Exercised (in dollars)	$ 58,481
Options vested and exercisable (in dollars)	5,526,601
Options vested and expected to vest (in dollars)	$ 6,450,115