Long-Term Debt (Schedule Of Long-Term Debt) (Details) (USD $)					12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 9.25% Senior Notes due 2020 [Member]	Jul. 30, 2012 9.25% Senior Notes due 2020 [Member]	Dec. 31, 2011 Long-Term Debt Allocated From The Predecessor [Member]	Dec. 31, 2011 Predecessor [Member]	Dec. 31, 2012 Senior Secured Revolving Credit Facility [Member]	Dec. 31, 2011 Senior Secured Revolving Credit Facility [Member]	Dec. 31, 2012 Letters Of Credit [Member]	Dec. 31, 2011 Letters Of Credit Allocated From The Predecessor [Member]
Debt Instrument [Line Items]
Credit Agreement, amount outstanding						$ 21,000,000	$ 470,000,000	$ 500,000,000	$ 23,488,000	$ 21,000,000
Long-term debt			296,076,000		115,000,000
Total long-term debt	766,076,000	615,000,000
Stated interest rate				9.25%
Long-term debt unamortized discount			$ 3,900,000
Long-term debt collateral					115.0