Long-Term Debt Senior Subordinated Notes (Details) (USD $)	3 Months Ended			12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Senior Subordinated Notes [Member]	Dec. 31, 2012 Senior Subordinated Notes [Member]	Mar. 08, 2013 Senior Subordinated Notes [Member]	Dec. 21, 2012 Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, stated interest rate			12.535%
Debt, short-term and long-term			$ 571,500,000	$ 621,500,000
Senior Subordinated Notes, repurchased amount					50,000,000	100,000,000
Premium, percentage of par value					106.27%	106.27%
Extinguishment of Debt, Fees Paid to Lenders					3,100,000	6,300,000
Write off of unamortized deferred financing costs			800,000	1,500,000
Extinguishment of Debt, Accrued Interest Paid to Lenders					2,500,000	2,300,000
Net loss on extinguishments of long-term debt	$ 3,900,000	$ 9,400,000	$ 3,900,000	$ 7,800,000