Stock Plans 3 (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2015
Options outstanding vested and expected to vest
Number of shares	3.0
Weighted average exercise price (in dollars per share)	$ 26.92
Weighted average remaining contractual life (in years)	7 years 4 months 24 days
Aggregate intrinsic value	$ 16.9	[1]
Options Outstanding Vested
Options outstanding vested and expected to vest
Number of shares	1.2
Weighted average exercise price (in dollars per share)	$ 25.92
Weighted average remaining contractual life (in years)	6 years 8 months 12 days
Aggregate intrinsic value	7.8	[1]
Options Outstanding Expected to Vest
Options outstanding vested and expected to vest
Number of shares	1.8	[2]
Weighted average exercise price (in dollars per share)	$ 27.56	[2]
Weighted average remaining contractual life (in years)	7 years 10 months 24 days	[2]
Aggregate intrinsic value	$ 9.1	[1],[2]

[1] These amounts represent the difference between the exercise price and $32.61, the closing price of the Company’s common stock on March 31, 2015, the last trading day of the Company’s fiscal year as reported on the NASDAQ Stock Market for all in-the-money options.

[2] Outstanding options expected to vest are net of estimated future forfeitures.