Financial Instruments and Fair Value (Details) (USD $) In Millions, except Per Share data, unless otherwise specified					0 Months Ended
	Dec. 31, 2013 Interest Rate Swap [Member]	Nov. 30, 2013 Interest Rate Swap [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] Other Long-term Liabilities and Current Liabilities [Member]	Dec. 31, 2012 Fair Value, Inputs, Level 2 [Member] Other Long-term Liabilities and Current Liabilities [Member]	Mar. 31, 2013 Common Stock Warrants [Member]	Mar. 12, 2007 Common Stock Warrants [Member]	Dec. 31, 2013 Senior Subordinated Notes [Member] 7.625% Senior Subordinated Notes due 2017	Dec. 31, 2012 Senior Subordinated Notes [Member] 7.625% Senior Subordinated Notes due 2017	Mar. 31, 2007 Convertible Notes [Member] Three Percent Senior Subordinated Convertible Notes Due 2012 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Cash Flow Hedge Derivative at Fair Value, Net			$ (0.3)	$ 0.6
Notional principal amount of derivative liability	18.4	75.0
Notional principal amount of derivative liability, at maturity	16.1	38.7
Interest rate swap, net loss amount expected to be reclassified in the next twelve months	$ (1.9)
Stated interest rate of debt instrument							7.625%	7.625%	3.00%
Investment Warrants, Exercise Price					$ 44.74	$ 45.09
Warrants, Exercise Price, Premium over Stock Price at Issuance						62.50%