Basis of Presentation (Schedule Of Stock-Based Compensation Expense By Statement Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	$ 907	$ 556
Tax benefit	0	0
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, net of tax	907	556
Cost of service revenues
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	68	43
Cost of product revenues
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	0	1
Research and development
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	154	95
Sales and marketing
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	347	316
General and administrative
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	$ 338	$ 101