Derivatives (Narrative) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Derivative Instruments, Gain [Line Items]
Period over which gain included in AOCI will be transferred to earnings, months	3 months
Expected earnings transfer	$ 1,000,000
Expected derivative maturity date	Dec. 31, 2013
Commodity Derivatives [Member]
Derivative Instruments, Gain [Line Items]
Accumulated OCI gain, net of tax	$ (963,000)	[1]	$ 9,912,000	[1]

[1] Net of taxes.