Stock-Based Compensation (Schedule Of Option Activity) (Details) (USD $)	9 Months Ended
	Dec. 31, 2012
Stock-Based Compensation Schedule Of Option Activity Details
Balance at March 31, 2012	6,034,335
Granted - options	932,000
Exercised	(777,487)
Cancelled/forfeited	(135,133)
Termination of plans	0
Balance at December 31, 2012	6,053,715
Shares available for grant, March 31, 2012	375,546
Change in options available for grant	4,100,000
Granted shares available for grant	(932,000)
Stock purchase rights/restricted stock units	(409,936)
Exercised shares available for grant	0
Cancelled/forfeited shares available for grant	135,133
Termination of plans shares available for grant	(43,004)
Shares available for grant, December 31, 2012	3,225,739
Weighted-average exercise price of options granted during period	$ 5.80
Weighted-average exercise price of options exercised during the period	$ 1.48
Weighted-average exercise price of options forfeited, cancelled or expired during the period	$ 4.01
Weighted-average exercise price of options termination of plans during period	$ 0
Weighted-average exercise price of options outstanding, December 31, 2012	$ 2.51