v2.4.0.8
Derivative Financial Instruments (Derivatives And Hedging-Overall-Subsequent Measurement) (Details) (Not Designated as Hedging Instrument [Member], USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]        
Derivative, Gain (Loss) on Derivative, Net $ (20,289) $ 15,710 $ (16,957) $ 11,282
NYMEX Commodity Contracts [Member] | Sales [Member]
       
Derivative Instruments, Gain (Loss) [Line Items]        
Derivative, Gain (Loss) on Derivative, Net (16,653) 12,342 (13,830) 10,581
NYMEX Commodity Contracts [Member] | Operating Expenses [Member]
       
Derivative Instruments, Gain (Loss) [Line Items]        
Derivative, Gain (Loss) on Derivative, Net (4,268) 3,348 (3,903) 1,462
Butane Futures Agreements [Member] | Cost of Sales [Member]
       
Derivative Instruments, Gain (Loss) [Line Items]        
Derivative, Gain (Loss) on Derivative, Net $ 632 $ 20 $ 776 $ (761)