Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Long-Term Debt (Details)

Long-Term Debt - Long-Term Debt (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Debt Disclosure [Abstract]    
8.50% Senior Notes $ 900,000us-gaap_UnsecuredLongTermDebt $ 900,000us-gaap_UnsecuredLongTermDebt
Debt premiums, net of amortization 13,057us-gaap_DebtInstrumentUnamortizedPremium 15,421us-gaap_DebtInstrumentUnamortizedPremium
Revolving bank credit facility 447,000us-gaap_LongTermLineOfCredit 290,000us-gaap_LongTermLineOfCredit
Total long-term debt 1,360,057us-gaap_LongTermDebt 1,205,421us-gaap_LongTermDebt
Long term debt, less current maturities $ 1,360,057us-gaap_LongTermDebtNoncurrent $ 1,205,421us-gaap_LongTermDebtNoncurrent