Basis of Presentation (Schedule Of Stock-Based Compensation Expense By Statement Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	$ 2,008	$ 1,106	$ 3,855	$ 2,013
Tax benefit	0	0	0	0
Stock-based employee compensation expense related to employee stock options and employee stock purchases, net of tax	2,008	1,106	3,855	2,013
Cost of service revenue
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	160	68	275	136
Cost of product revenue
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	0	0	0	0
Research and development
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	315	141	629	295
Sales and marketing
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	910	393	1,654	740
General and administrative
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	$ 623	$ 504	$ 1,297	$ 842