Stock-Based Compensation (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stock-Based Compensation [Abstract]
Stock-based compensation cost	$ 1.7	$ 0.7	$ 2.7	$ 1.6
Assumptions used in determining fair value of options [Abstract]
Expected life of awards in years			6 years 3 months 18 days	6 years 3 months 18 days
Risk-free interest rate (in hundredths)			2.10%	1.30%
Expected volatility of the Company's stock (in hundredths)			76.10%	88.70%
Expected dividend yield on the Company's stock (in hundredths)			0.00%	0.00%
Unrecognized compensation cost and recognition period [Abstract]
Unrecognized Compensation Cost	11.3		11.3
Weighted Average Remaining Service Period in Years			2 years 8 months 12 days
Stock options [Member]
Type and fair value of stock-based compensation awards granted [Abstract]
Options granted (in shares)			0.1	0.2
Options, grant date fair value (in dollars per share)			$ 10.21	$ 7.76
Unrecognized compensation cost and recognition period [Abstract]
Unrecognized Compensation Cost	2.2		2.2
Weighted Average Remaining Service Period in Years			3 years 1 month 6 days
Restricted Stock [Member]
Type and fair value of stock-based compensation awards granted [Abstract]
Stock granted (in shares)			0.2	0.3
Fair value of stock granted (in dollars per share)			$ 14.94	$ 10.40
Unrecognized compensation cost and recognition period [Abstract]
Unrecognized Compensation Cost	5.8		5.8
Weighted Average Remaining Service Period in Years			2 years 10 months 24 days
Restricted stock - Performance Based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period			3 years
Type and fair value of stock-based compensation awards granted [Abstract]
Stock granted (in shares)			0.2	0.2
Fair value of stock granted (in dollars per share)			$ 14.94	$ 10.40
Unrecognized compensation cost and recognition period [Abstract]
Unrecognized Compensation Cost	$ 3.3		$ 3.3
Weighted Average Remaining Service Period in Years			2 years 2 months 12 days
Unrestricted stock [Member]
Type and fair value of stock-based compensation awards granted [Abstract]
Stock granted (in shares)			0.1	0
Fair value of stock granted (in dollars per share)			$ 14.83	$ 0