Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Additional Information (Details)

v3.3.1.900
Long-Term Debt - Additional Information (Details) - USD ($)
 1 Months Ended 12 Months Ended
May. 31, 2015
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Debt Instrument [Line Items]        
Minimum borrowing base amount allowed before term loan purchase   $ 200,000,000    
Letter of credit maximum amount outstanding prior to repurchase of term loan   100,000,000    
Debt issuance costs write-down/amortization of debt items   $ 4,411,000 $ 701,000 $ 1,645,000
Revolving bank credit facility     $ 447,000,000  
London Interbank Offered Rate (LIBOR)        
Debt Instrument [Line Items]        
Debt instrument, basis spread on variable rate   1.00%    
Federal Funds Effective Swap Rate        
Debt Instrument [Line Items]        
Debt instrument, basis spread on variable rate   0.50%    
Maximum        
Debt Instrument [Line Items]        
Percentage of hedging contracts   75.00%    
First lien leverage ratio   150.00%    
Current ratio   100.00%    
Secured debt leverage ratio   350.00%    
Maximum | Thereafter        
Debt Instrument [Line Items]        
Current ratio   100.00%    
Minimum        
Debt Instrument [Line Items]        
First lien leverage ratio   100.00%    
Current ratio   75.00%    
Secured debt leverage ratio   100.00%    
Minimum | Thereafter        
Debt Instrument [Line Items]        
Current ratio   100.00%    
Revolving Credit Facility        
Debt Instrument [Line Items]        
Line of credit maximum amount outstanding prior to repurchase of term loan   $ 0    
8.50% Senior Notes due June 2019        
Debt Instrument [Line Items]        
Debt instrument interest rate   8.50% 8.50%  
Debt instrument payment terms   semi-annually in arrears on June 15 and December 15    
Effective interest rate   8.40%    
Senior notes maturity date   Jun. 15, 2019    
Principal   $ 900,000,000 $ 900,000,000  
9.00% Term Loan due 2020        
Debt Instrument [Line Items]        
Debt instrument interest rate 9.00% 9.00%    
Debt instrument payment terms   Interest on the 9.00% Term Loan is payable in arrears semi-annually on May 15 and November 15    
Effective interest rate 9.70%      
Debt instruments, discount rate 1.00%      
Principal   $ 300,000,000    
Revolving Bank Credit Facility Due November 2018        
Debt Instrument [Line Items]        
Effective interest rate   3.30%    
Credit agreement expiration date   Nov. 08, 2018    
Borrowings and letters of credit, repayment terms   To the extent borrowings and letters of credit outstanding exceed the redetermined borrowing base, such excess or deficiency is required to be repaid within 90 days in three equal monthly payments.    
Revolving bank credit facility borrowing base   $ 350,000,000    
Revolving bank credit facility interest rate description   Borrowings under the revolving bank credit facility bear interest at the applicable London Interbank Offered Rate (“LIBOR”) plus a margin that varies from 2.25% to 3.25% depending on the level of total borrowings under the Credit Agreement, or an alternative base rate equal to the greater of (a) Prime Rate, (b) Federal Funds Rate plus 0.5%, and (c) LIBOR plus 1.0%, plus applicable margin ranging from 1.25% to 2.25%.    
Debt issuance costs write-down/amortization of debt items   $ 3,200,000    
Revolving bank credit facility   0 447,000,000  
Letters of credit outstanding   $ 900,000 $ 600,000  
Revolving Bank Credit Facility Due November 2018 | Maximum        
Debt Instrument [Line Items]        
Unused portion of the borrowing base commitment fee   0.50%    
Revolving Bank Credit Facility Due November 2018 | Maximum | London Interbank Offered Rate (LIBOR)        
Debt Instrument [Line Items]        
Debt instrument, basis spread on variable rate   3.25%    
Revolving Bank Credit Facility Due November 2018 | Maximum | London Interbank Offered Rate Additional Applicable Margin        
Debt Instrument [Line Items]        
Debt instrument, basis spread on variable rate   2.25%    
Revolving Bank Credit Facility Due November 2018 | Minimum        
Debt Instrument [Line Items]        
Unused portion of the borrowing base commitment fee   0.375%    
Revolving Bank Credit Facility Due November 2018 | Minimum | London Interbank Offered Rate (LIBOR)        
Debt Instrument [Line Items]        
Debt instrument, basis spread on variable rate   2.25%    
Revolving Bank Credit Facility Due November 2018 | Minimum | London Interbank Offered Rate Additional Applicable Margin        
Debt Instrument [Line Items]        
Debt instrument, basis spread on variable rate   1.25%    
Revolving Bank Credit Facility Due November 2018 | Letter Of Credit        
Debt Instrument [Line Items]        
Revolving bank credit facility maximum lender commitment   $ 300,000,000