Long-Term Debt--Senior Secured Revolving Credit Facility (Details) (USD $)	3 Months Ended	1 Months Ended	6 Months Ended			1 Months Ended	3 Months Ended
	Jun. 30, 2014 Divestiture	Jun. 30, 2014 Line of Credit	Jun. 30, 2014 Line of Credit	May 23, 2014 Line of Credit	Apr. 22, 2014 Line of Credit	Aug. 14, 2014 Subsequent Event Divestiture	Jul. 31, 2014 Subsequent Event Divestiture	Jul. 18, 2014 Subsequent Event Line of Credit	Aug. 14, 2014 Minimum Subsequent Event Line of Credit
Line of Credit Facility [Line Items]
Maturity date			Nov. 01, 2017
Proceeds from senior secured revolving credit facility			$ 110,000,000
Repayments on senior secured revolving credit facility			133,000,000
Number of divestitures	2					2	4
Borrowing base amount				$ 532,000,000	$ 600,000,000			$ 484,500,000
Reduction in availability under the revolving credit facility, as a percentage of the borrowing base		10.00%
Ratio of credit availability to liability on overhedged production									2