Stockholders' Equity Option Activity (Details) (USD $)	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Stockholders Equity Option Activity Details
Balance at beginning of period	6,002,382	5,991,544	6,034,335
Granted	1,110,466	1,465,400	932,000
Exercised	(1,326,385)	(1,283,470)	(835,246)
Cancelled/forfeited	(458,556)	(171,092)	(139,545)
Balance at end of period	5,327,907	6,002,382	5,991,544
Options, Vested and expected to vest	5,327,907
Options, Exercisable at end of period	3,243,325
Weighted-average exercise price of options outstanding, at beginning of period	$ 4.14	$ 2.52	$ 1.90
Weighted-average exercise price of options granted during period	$ 7.29	$ 9.66	$ 5.80
Weighted-average exercise price of options exercised during the period	$ 1.87	$ 2.75	$ 1.49
Weighted-average exercise price of options forfeited, cancelled or expired during the period	$ 6.06	$ 5.25	$ 4.00
Weighted-average exercise price of options outstanding at end of period	$ 5.19	$ 4.14	$ 2.52
Options, Vested and Expected to Vest, Weighted Average Exercise Price	$ 5.19
Weighted-Average Exercise Prices, Exercisable at end of period	$ 3.35