Stock Plans 3 (Details) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2018 USD ($) $ / shares shares
Options outstanding vested and expected to vest
Number of shares | shares	4.1
Weighted average exercise price (in dollars per share) | $ / shares	$ 29.37
Weighted average remaining contractual life (in years)	7 years
Aggregate intrinsic value | $	$ 18.7	[1]
Options Outstanding, Vested
Options outstanding vested and expected to vest
Number of shares | shares	2.4
Weighted average exercise price (in dollars per share) | $ / shares	$ 27.79
Weighted average remaining contractual life (in years)	5 years 10 months 24 days
Aggregate intrinsic value | $	$ 14.6	[1]
Options Outstanding, Expected to Vest
Options outstanding vested and expected to vest
Number of shares | shares	1.7	[2]
Weighted average exercise price (in dollars per share) | $ / shares	$ 31.57	[2]
Weighted average remaining contractual life (in years)	8 years 6 months	[2]
Aggregate intrinsic value | $	$ 4.1	[1],[2]

[1] These amounts represent the difference between the exercise price and $33.90, the closing price of the Company’s common stock on March 29, 2018, 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.