Derivative Financial Instruments (Textuals) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014
Derivative [Line Items]
Total Derivative Counterparties	16
Primary Derivative Counterparties	10
Percent of future hedged production with primary counterparties	85.00%
Number of counterparties holding more than 25 percent of future hedge position.	0
Concentraction Of Future Hedged Production	15.00%
Year2015 [Member] | Natural gas contracts [Member] | Swap [Member]
Derivative [Line Items]
Derivative, Swap Type, Average Fixed Price	4.28
Volume In Mmbtus	49,275,000
Year2015 [Member] | Oil contracts [Member] | Swap [Member]
Derivative [Line Items]
Volume in MBbls	8,845,000
Derivative, Swap Type, Average Fixed Price	90.42
Year 2016 [Member] | Oil contracts [Member] | Swaption [Member]
Derivative [Line Items]
Volume in MBbls	732,000
Derivative, Swap Type, Average Fixed Price	91
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 1