Equity Offering (Details) (USD $)	12 Months Ended			3 Months Ended			3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Senior secured notes [Member]	Jun. 30, 2012 Senior secured notes [Member]	Dec. 29, 2009 Senior secured notes [Member]	Jun. 30, 2012 Issuance of Equity [Member] Senior secured notes [Member]	Jun. 30, 2012 Common Stock [Member] Issuance of Equity [Member]	May 08, 2012 Common Stock [Member] Issuance of Equity [Member]
Equity Offering [Line Items]
Stock Issued During Period, Shares, New Issues								4,000,000
Stock Issued During Period, Value, Per Share Offering Price									$ 20.75
Stock Issuance Costs								$ 4,000,000
Proceeds from sale of common stock	79,040,000	0	0					79,000,000
Proceeds Used for Early Extinguishment of Debt							54,900,000
Debt Instrument, Interest Rate, Stated Percentage						9.75%
Extinguishment of Debt, Amount				$ 200,000,000	$ 50,000,000