Equity Offering (Details) (USD $)	6 Months Ended				6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	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				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			$ 50,000,000