Stock-Based Compensation (Schedule Of Stock-Based Compensation Expense By Statement Of Operations) (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	$ 506,000	$ 329,000	$ 1,062,000	$ 595,000
Tax benefit	0	0	0	0
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, net of tax	506,000	329,000	1,062,000	595,000
Cost of service revenues
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	43,000	26,000	86,000	46,000
Cost of product revenues
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	0	0	1,000	0
Research and development
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	75,000	56,000	170,000	104,000
Sales and marketing
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	308,000	199,000	624,000	355,000
General and administrative
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	$ 80,000	$ 48,000	$ 181,000	$ 90,000