Stockholders' Equity - Common Shares Reserved for Issuance (Details) - shares shares in Thousands	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Class of Stock [Line Items]
Options granted and outstanding		1,794	2,409	3,492
Common stock reserved for issuance	10,325
Stock Options
Class of Stock [Line Items]
Options granted and outstanding	1,571
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Restricted Stock Units granted and outstanding	4,704	4,328	6,105	6,444
Options and Restricted Stock Units
Class of Stock [Line Items]
Options and RSUs authorized for future grants	2,836
Employee Stock Purchase Plan
Class of Stock [Line Items]
Options granted and outstanding	1,214