Stock-Based Compensation (Summary Of Stock Options Outstanding And Exercisable) (Details) (USD $)			6 Months Ended
	Sep. 30, 2012	Mar. 31, 2012	Sep. 30, 2012 $0.55 - $1.26	Sep. 30, 2012 $1.27 - $1.72	Sep. 30, 2012 $1.73 - $3.17	Sep. 30, 2012 $3.18 - $4.95	Sep. 30, 2012 $4.96 - $5.87
Range of Exercise Prices, Minimum			$ 0.55	$ 1.27	$ 1.73	$ 3.18	$ 4.96
Range of Exercise Prices, Maximum			$ 1.26	$ 1.72	$ 3.17	$ 4.95	$ 5.87
Options Outstanding, Number of Shares	6,379,105	6,034,335	1,887,000	1,554,919	1,319,894	765,292	852,000
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 2.46		$ 1.04	$ 1.53	$ 2.41	$ 4.13	$ 5.87
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)			5.2	2.8	5.9	6.9	9.9
Options Outstanding, Aggregate Intrinsic Value			$ 10,421,645	$ 7,828,087	$ 5,476,782	$ 1,859,600	$ 587,880
Options Exercisable, Number of Shares			1,887,000	1,554,919	841,505	276,581	17,743
Options Exercisable, Weighted-Average Exercise Price Per Share			$ 1.04	$ 1.53	$ 2.19	$ 3.93	$ 5.87
Options Exercisable, Aggregate Intrinsic Value			$ 10,421,645	$ 7,828,087	$ 3,674,501	$ 727,527	$ 12,242