Significant Accounting Policies (Schedule Of Stock-Based Compensation Expense By Statement Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	$ 2,634	$ 1,506	$ 458
Tax benefit	0	0	0
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, net of tax	2,634	1,506	458
Cost of service revenues
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	211	129	50
Cost of product revenues
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	0	0	0
Research and development
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	428	260	111
Sales and marketing
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	1,363	859	192
General and administrative
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	$ 632	$ 258	$ 105