Fair Value Measurements (Unobservable Inputs In Level 3 Valuations Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (Weighted Average [Member], Significant Unobservable Inputs (Level 3) [Member], Fair Value, Measurements, Recurring [Member])	Jun. 30, 2014	Dec. 31, 2013
Inventory Related Payables [Member]
Unobservable inputs in Level 3 Valuations of Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Basis	17.80%	13.20%
Transportation cost	0.00%	0.00%
Commodity Derivative Contracts Losses [Member]
Unobservable inputs in Level 3 Valuations of Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Basis	19.60%	17.60%
Transportation cost	6.40%	12.30%
Inventories Carried At Market [Member]
Unobservable inputs in Level 3 Valuations of Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Basis	16.90%	21.90%
Transportation cost	5.00%	12.30%
Commodity Derivative Contracts Gains [Member]
Unobservable inputs in Level 3 Valuations of Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Basis	22.60%	22.80%
Transportation cost	4.90%	32.50%