Stock-based Compensation Stock-Based Compensation Expense By Statement Of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	$ 8,911	$ 6,351
Cost of service revenue
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	458	391
Cost of product revenue
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	0	0
Research and development
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	2,194	1,337
Sales and marketing
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	3,845	2,647
General and administrative
Stock-based employee compensation expense related to employee stock options and employee stock purchases, pre tax	$ 2,414	$ 1,976