Derivatives (Effect Of Derivative Instruments Recognized In Statement Of Income, Not Designated As Hedging Instruments) (Details) (Not Designated as Hedging Instrument [Member], Commodity Derivatives [Member], USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Income	$ 19,841,000		$ (13,508,000)		$ (9,234,000)		$ (3,456,000)
Amount settled during the period	(1,000,000)		(2,400,000)		(19,000,000)		(1,600,000)
Gain (loss) on derivatives not designated as hedges and hedge ineffectiveness, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Income	$ 19,841,000	[1]	$ (13,508,000)	[1]	$ (9,234,000)	[2]	$ (3,456,000)	[2]

[1] Amounts settled during the 2014 and 2013 periods include losses of $1.0 million and $2.4 million, respectively.

[2] Amounts settled during the 2014 and 2013 periods include losses of $19.0 million and $1.6 million, respectively.