Stock-Based Compensation (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock-Based Compensation [Abstract]
Stock-based compensation cost	$ 0.7	$ 0.7	$ 1.6	$ 1.6
Performance period			3 years
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)			1.30%	0.90%
Expected volatility of the Company's stock (in hundredths)			88.70%	87.40%
Expected dividend yield on the Company's stock (in hundredths)			0.00%	0.00%
Unrecognized compensation cost and recognition period [Abstract]
Unrecognized Compensation Cost	9.1		9.1
Weighted Average Remaining Service Period in Years			2 years 9 months 18 days
Stock options [Member]
Type and fair value of stock-based compensation awards granted [Abstract]
Options granted (in shares)			0.2	0.2
Options, grant date fair value (in dollars per share)			$ 7.76	$ 4.26
Unrecognized compensation cost and recognition period [Abstract]
Unrecognized Compensation Cost	1.8		1.8
Weighted Average Remaining Service Period in Years			2 years 9 months 18 days
Restricted stock - retention [Member]
Type and fair value of stock-based compensation awards granted [Abstract]
Stock granted (in shares)			0.3	0.4
Fair value of stock granted (in dollars per share)			$ 10.40	$ 5.80
Unrecognized compensation cost and recognition period [Abstract]
Unrecognized Compensation Cost	4.8		4.8
Weighted Average Remaining Service Period in Years			3 years 1 month 6 days
Restricted stock - performance based [Member]
Type and fair value of stock-based compensation awards granted [Abstract]
Stock granted (in shares)			0.2	0.4
Fair value of stock granted (in dollars per share)			$ 10.40	$ 5.75
Unrecognized compensation cost and recognition period [Abstract]
Unrecognized Compensation Cost	$ 2.5		$ 2.5
Weighted Average Remaining Service Period in Years			2 years 3 months 18 days