Derivative Financial Instruments (Derivatives And Hedging-Nondesignated) (Details) (Not Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 18	$ 430
Derivative Liability, Fair Value, Gross Liability	3,269	7,021
NYMEX Commodity Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	48
NYMEX Commodity Contracts [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	3,217	7,021
Butane Futures Agreements [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	18	382
Butane Futures Agreements [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 52	$ 0