Fair Value Measurements (Details)
 12 Months Ended
Dec. 31, 2016
USD ($)
$ / item
Dec. 31, 2015
USD ($)
$ / item
Jun. 01, 2015
USD ($)
Dec. 31, 2014
USD ($)
Jun. 19, 2014
USD ($)
Assets:          
Pension plans $ 16,777,000 $ 16,886,000      
Liabilities:          
Stated interest rate (as a percent)       6.25%  
Senior Notes 6.25 Percent Due 2022          
Liabilities:          
Stated interest rate (as a percent)       6.25% 6.25%
Face value of debt instrument 375,000,000 375,000,000   $ 375,000,000 $ 375,000,000
Fair value of debt instrument 361,163,000 307,500,000      
Senior Notes 7.00 Percent Due 2023 [Member]          
Liabilities:          
Stated interest rate (as a percent)     7.00%    
Face value of debt instrument 300,000,000 300,000,000 $ 300,000,000    
Fair value of debt instrument 289,500,000 249,000,000      
Level 3          
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]          
Fair Value, beginning of period 64,000        
Purchases 1,435,000        
Sales (1,770,000)        
Recognized gains (losses) recorded in cost of sales 147,000        
Unrecognized gains (losses) recorded in cost of sales (247,000)        
Fair Value, end of period $ (371,000) $ 64,000      
Minimum | Level 3          
Liabilities:          
Estimated margin, crude oil (in dollars per barrel) | $ / item 4.05 2.10      
Estimated margin, propane (in dollars per barrel) | $ / item 4.20 2.1      
Estimates Margin for Transportation and Throughput Costs Per Barrel | $ / item   4.00      
Maximum | Level 3          
Liabilities:          
Estimated margin, crude oil (in dollars per barrel) | $ / item 6.50 9.66      
Estimated margin, propane (in dollars per barrel) | $ / item 10.50 9.66      
Estimates Margin for Transportation and Throughput Costs Per Barrel | $ / item   13.55      
Recurring basis          
Assets:          
Pension plans $ 16,777,000 $ 16,886,000      
Total assets 65,813,000 114,322,000      
Liabilities:          
Total liabilities (28,583,000) (35,254,000)      
Recurring basis | Forward derivative contracts          
Assets:          
Derivative assets 20,655,000 66,099,000      
Liabilities:          
Derivative liabilities (27,151,000) (31,255,000)      
Recurring basis | Swap agreements and option contracts          
Liabilities:          
Derivative liabilities (262,000) (656,000)      
Recurring basis | Foreign Currency Derivatives          
Assets:          
Derivative assets   10,000      
Recurring basis | Interest Rate Cap          
Assets:          
Derivative assets 727,000        
Recurring basis | Interest Rate Swaps          
Liabilities:          
Derivative liabilities (1,170,000) (3,343,000)      
Recurring basis | Exchange-Traded Derivatives          
Assets:          
Exchange-traded/cleared derivative instruments 27,654,000 31,327,000      
Cash collateral netting 98,344,000 (64,040,000)      
Recurring basis | Level 1          
Assets:          
Pension plans 16,777,000 16,886,000      
Total pre-netting liabilities (53,913,000)        
Total assets   112,253,000      
Recurring basis | Level 1 | Exchange-Traded Derivatives          
Assets:          
Exchange-traded/cleared derivative instruments (70,690,000) 95,367,000      
Recurring basis | Level 2          
Assets:          
Total assets 19,699,000 62,392,000      
Liabilities:          
Total liabilities (26,529,000) (31,601,000)      
Recurring basis | Level 2 | Forward derivative contracts          
Assets:          
Derivative assets 18,972,000 62,382,000      
Liabilities:          
Derivative liabilities (25,097,000) (27,602,000)      
Recurring basis | Level 2 | Swap agreements and option contracts          
Liabilities:          
Derivative liabilities (262,000) (656,000)      
Recurring basis | Level 2 | Foreign Currency Derivatives          
Assets:          
Derivative assets   10,000      
Recurring basis | Level 2 | Interest Rate Cap          
Assets:          
Derivative assets 727,000        
Recurring basis | Level 2 | Interest Rate Swaps          
Liabilities:          
Derivative liabilities (1,170,000) (3,343,000)      
Recurring basis | Level 3          
Assets:          
Total assets 1,683,000 3,717,000      
Liabilities:          
Total liabilities (2,054,000) (3,653,000)      
Recurring basis | Level 3 | Forward derivative contracts          
Assets:          
Derivative assets 1,683,000 3,717,000      
Liabilities:          
Derivative liabilities $ (2,054,000) $ (3,653,000)