Stockholders' Equity - Employee Stock Purchase Plan (Details) - Employee Stock Purchase Plan - 2012 Employee Stock Purchase Plan - USD ($) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Aug. 31, 2014	Aug. 30, 2012
Class of Stock [Line Items]
Common stock reserved for issuance (in shares)				1.8
Additional shares reserved for issuance (in shares)			2.0
Percentage of purchase price of common stock equal to fair market value	85.00%
Shares available for future issuance (in shares)	1.6
Average purchase price of shares purchased (in dollars per share)	$ 4.46	$ 7.09
Number of shares purchased (in shares)	0.2	0.2
Intrinsic value of shares purchased	$ 0.4	$ 0.3