Certain Financial Statement Information - Net loss per share (Details) - shares shares in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities that have been excluded from the net loss per share computation	6,658	6,371	8,733
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities that have been excluded from the net loss per share computation	1,571	1,794	2,409
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities that have been excluded from the net loss per share computation	4,704	4,328	6,105
ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities that have been excluded from the net loss per share computation	383	249	219