Stock-based Compensation (Narrative) (Details) $ in Millions	6 Months Ended
Sep. 30, 2015 USD ($)
Stock-Based Awards
Unamortized stock-based compensation expense related to unvested stock awards	$ 38.1
Weighted average period of recognition for unrecognized compensation costs (in years)	2 years 241 days
Employee Stock Purchase Plan
Unamortized stock-based compensation expense related to unvested stock awards	$ 0.6
Weighted average period of recognition for unrecognized compensation costs (in years)	180 days

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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