Derivative Commodity Instruments (Fair Values Of Derivative Instruments In Consolidated Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Total asset derivatives	$ 296	$ 14,427
Total liability derivatives	176	13,694
Accounts Receivable, Net [Member] | Commodity Forward Contracts [Member]
Derivative [Line Items]
Commodity forward contracts	0	13,032
Derivatives Not Designated as Hedging Instruments, Asset Derivatives	296	1,395
Accrued Liabilities [Member] | Commodity Forward Contracts [Member]
Derivative [Line Items]
Derivatives Designated as Hedging Instruments, Liability Derivatives	0	399
Derivatives Not Designated as Hedging Instruments, Liability Derivatives	$ 176	$ 13,295