Stock-Based Compensation (Summary Of Stock Options Outstanding And Exercisable) (Details) (USD $)			3 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2012 $0.55 - $1.15	Jun. 30, 2012 $1.16 - $1.32	Jun. 30, 2012 $1.33 - $1.72	Jun. 30, 2012 $1.73 - $2.81	Jun. 30, 2012 $2.82 - $4.95
Range of Exercise Prices, Minimum			$ 0.55	$ 1.16	$ 1.33	$ 1.73	$ 2.82
Range of Exercise Prices, Maximum			$ 1.15	$ 1.32	$ 1.72	$ 2.81	$ 4.95
Options Outstanding, Number of Shares	5,995,477	6,034,335	1,217,168	1,340,843	1,291,166	1,216,800	929,500
Options Outstanding, Weighted-Average Exercise Price Per Share	$ 1.89	$ 1.90	$ 0.87	$ 1.27	$ 1.60	$ 2.32	$ 3.98
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)			5.2	4.2	2.7	5.6	7.6
Options Outstanding, Aggregate Intrinsic Value	$ 13,966,254		$ 4,049,066	$ 3,928,182	$ 3,358,141	$ 2,282,315	$ 348,550
Options Exercisable, Number of Shares	4,945,866		1,217,168	1,340,843	1,291,166	850,523	246,166
Options Exercisable, Weighted-Average Exercise Price Per Share			$ 0.87	$ 1.27	$ 1.60	$ 2.20	$ 3.84
Options Exercisable, Aggregate Intrinsic Value	$ 13,170,599		$ 4,049,066	$ 3,928,182	$ 3,358,141	$ 1,702,675	$ 132,535