Stockholder's Equity Stock Options Outstanding And Exercisable (Details) (USD $)	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Options Outstanding, Number of Shares	5,327,907	6,002,382	5,991,544	6,034,335
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 5.19	$ 4.14	$ 2.52	$ 1.90
Options Exercisable, Number of Shares	3,243,325
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 3.35
$0.55 - $1.26
Range of Exercise Prices, Minimum	$ 0.55
Range of Exercise Prices, Maximum	$ 1.26
Options Outstanding, Number of Shares	1,095,000
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 1.11
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	2 years 329 days
Options Outstanding, Aggregate Intrinsic Value	$ 7,982,430
Options Exercisable, Number of Shares	1,095,000
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 1.11
Options Exercisable, Aggregate Intrinsic Value	7,982,430
$1.27 - $3.92
Range of Exercise Prices, Minimum	$ 1.27
Range of Exercise Prices, Maximum	$ 3.92
Options Outstanding, Number of Shares	1,067,933
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 1.63
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	1 year 146 days
Options Outstanding, Aggregate Intrinsic Value	7,233,393
Options Exercisable, Number of Shares	1,064,403
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 1.62
Options Exercisable, Aggregate Intrinsic Value	7,214,201
$4.25 - $6.86
Range of Exercise Prices, Minimum	$ 4.25
Range of Exercise Prices, Maximum	$ 6.86
Options Outstanding, Number of Shares	1,543,322
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 6.10
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	8 years 73 days
Options Outstanding, Aggregate Intrinsic Value	3,543,355
Options Exercisable, Number of Shares	622,739
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 5.50
Options Exercisable, Aggregate Intrinsic Value	1,803,291
$7.52 - $9.74
Range of Exercise Prices, Minimum	$ 7.52
Range of Exercise Prices, Maximum	$ 9.74
Options Outstanding, Number of Shares	1,471,652
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 9.26
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	8 years 256 days
Options Outstanding, Aggregate Intrinsic Value	156,354
Options Exercisable, Number of Shares	415,871
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 9.62
Options Exercisable, Aggregate Intrinsic Value	1,083
$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 292 days
Options Outstanding, Aggregate Intrinsic Value	0
Options Exercisable, Number of Shares	45,312
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 11.09
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	5,327,907
Options Outstanding, Aggregate Intrinsic Value	18,915,533
Options Exercisable, Number of Shares	3,243,325
Options Exercisable, Aggregate Intrinsic Value	$ 17,001,005