Stock-Based Compensation (Schedule Of Option Activity) (Details) (USD $)	6 Months Ended
	Sep. 30, 2012
Stock-Based Compensation Schedule Of Option Activity Details
Balance at March 31, 2012	6,034,335
Granted - options	890,000
Exercised	(476,719)
Cancelled/forfeited	(68,511)
Termination of plans	0
Balance at September 30, 2012	6,379,105
Shares available for grant, March 31, 2012	375,546
Change in options available for grant	4,100,000
Granted shares available for grant	(890,000)
Stock purchase rights/restricted stock units	(369,436)
Exercised shares available for grant	0
Cancelled/forfeited shares available for grant	68,511
Termination of plans shares available for grant	(41,051)
Shares available for grant, September 30, 2012	3,243,570
Weighted-average exercise price of options granted during period	$ 5.80
Weighted-average exercise price of options exercised during the period	$ 1.40
Weighted-average exercise price of options forfeited, cancelled or expired during the period	$ 4.42
Weighted-average exercise price of options termination of plans during period	$ 0
Weighted-average exercise price of options outstanding, September 30, 2012	$ 2.46