Derivative Activities (Gains (Losses) Of Derivative Contacts By Statement Of Operations Location) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instrument	$ (67,567)		$ 50,329		$ (91,215)		$ 34,205
Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instrument	(65,757)	[1]	49,523	[1]	(88,922)	[1]	33,517	[1]
Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instrument	$ (1,810)	[2]	$ 806	[2]	$ (2,293)	[2]	$ 688	[2]

[1] Gain (loss) on commodity derivative contracts is located in other income (expense), net in the consolidated statements of operations.

[2] Gain (loss) on interest rate derivatives contracts is recorded as part of interest expense, net and is located in other income (expense) in the consolidated statements of operations.