Stock-based Compenstaion Stock Options Outstanding And Exercisable (Details) - USD ($)	6 Months Ended
	Sep. 30, 2015	Mar. 31, 2015
Options Outstanding, Number of Shares	5,530,320	5,327,907
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 5.80	$ 5.19
Options Exercisable, Number of Shares	3,166,470
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 4.02
$0.55 - $1.27
Range of Exercise Prices, Minimum	0.55
Range of Exercise Prices, Maximum	$ 1.27
Options Outstanding, Number of Shares	1,303,775
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 1.14
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	2 years 72 days
Options Outstanding, Aggregate Intrinsic Value	$ 9,301,445
Options Exercisable, Number of Shares	1,303,775
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 1.14
Options Exercisable, Aggregate Intrinsic Value	$ 9,301,445
$1.33 - $5.87
Range of Exercise Prices, Minimum	$ 1.33
Range of Exercise Prices, Maximum	$ 5.87
Options Outstanding, Number of Shares	1,241,055
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 4.03
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	4 years 288 days
Options Outstanding, Aggregate Intrinsic Value	$ 5,265,678
Options Exercisable, Number of Shares	1,096,699
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 3.81
Options Exercisable, Aggregate Intrinsic Value	$ 4,894,609
$6.86 - $8.15
Range of Exercise Prices, Minimum	$ 6.86
Range of Exercise Prices, Maximum	$ 8.15
Options Outstanding, Number of Shares	1,338,508
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 7.38
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	9 years 108 days
Options Outstanding, Aggregate Intrinsic Value	$ 1,192,736
Options Exercisable, Number of Shares	154,763
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 7.00
Options Exercisable, Aggregate Intrinsic Value	$ 196,205
$8.54 - $9.74
Range of Exercise Prices, Minimum	$ 8.54
Range of Exercise Prices, Maximum	$ 9.74
Options Outstanding, Number of Shares	1,496,982
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 9.39
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	8 years 144 days
Options Outstanding, Aggregate Intrinsic Value	$ 0
Options Exercisable, Number of Shares	547,171
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 9.63
Options Exercisable, Aggregate Intrinsic Value	$ 0
$10.97 - $11.26
Range of Exercise Prices, Minimum	$ 10.97
Range of Exercise Prices, Maximum	$ 11.26
Options Outstanding, Number of Shares	150,000
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 11.11
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	8 years 108 days
Options Outstanding, Aggregate Intrinsic Value	$ 0
Options Exercisable, Number of Shares	64,062
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 11.10
Options Exercisable, Aggregate Intrinsic Value	$ 0
$0.55 - $11.26
Range of Exercise Prices, Minimum	$ 0.55
Range of Exercise Prices, Maximum	$ 11.26
Options Outstanding, Number of Shares	5,530,320
Options Outstanding, Aggregate Intrinsic Value	$ 15,759,859
Options Exercisable, Number of Shares	3,166,470
Options Exercisable, Aggregate Intrinsic Value	$ 14,392,259