Derivative Financial Instruments (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2013 Rollfactor Swap Contracts [Member]	Feb. 20, 2014 Oil contracts [Member] Rollfactor Swap Contracts for March Through December 2014 [Member]	Feb. 20, 2014 Oil contracts [Member] Rollfactor Swap Contracts for Year 2 [Member]	Dec. 31, 2013 Oil contracts [Member] Collar Contracts With Short Puts for Next Twelve Months [Member]	Feb. 20, 2014 Oil contracts, price per bbl [Member] Rollfactor Swap Contracts for March Through December 2014 [Member]	Feb. 20, 2014 Oil contracts, price per bbl [Member] Rollfactor Swap Contracts for Year 2 [Member]	Dec. 31, 2013 Oil contracts, price per bbl [Member] Collar Contracts With Short Puts for Next Twelve Months [Member]	Dec. 31, 2013 Oil contracts, price per bbl [Member] Collar Contracts With Short Puts for Next Twelve Months [Member] Short Put [Member]	Dec. 31, 2013 NGL contract, in BBLS [Member] Collar Contracts With Short Puts for Next Twelve Months [Member]	Dec. 31, 2013 NGL contract, in BBLS [Member] Collar Contracts for Next Twelve Months [Member]	Feb. 20, 2014 NGL contract, in BBLS [Member] Swap Contracts for March Through December 2014 [Member]	Feb. 20, 2014 NGL contract, in BBLS [Member] Swap Contracts for April Through October 2014 [Member]	Dec. 31, 2013 NGL contracts, price per BBL [Member] Collar Contracts With Short Puts for Next Twelve Months [Member]	Dec. 31, 2013 NGL contracts, price per BBL [Member] Collar Contracts With Short Puts for Next Twelve Months [Member] Short Put [Member]	Dec. 31, 2013 NGL contracts, price per BBL [Member] Collar Contracts for Next Twelve Months [Member]	Feb. 20, 2014 NGL contracts, price per BBL [Member] Swap Contracts for March Through December 2014 [Member]	Feb. 20, 2014 NGL contracts, price per BBL [Member] Swap Contracts for April Through October 2014 [Member]	Dec. 31, 2013 Gas contracts, in MMBTU [Member] Collar Contracts With Short Puts for Next Twelve Months [Member]	Feb. 20, 2014 Gas contracts, in MMBTU [Member] Basis Swap Contracts for April Through December 2014 [Member]	Dec. 31, 2013 Gas contracts, price per MMBTU [Member] Collar Contracts With Short Puts for Next Twelve Months [Member]	Dec. 31, 2013 Gas contracts, price per MMBTU [Member] Collar Contracts With Short Puts for Next Twelve Months [Member] Short Put [Member]	Feb. 20, 2014 Gas contracts, price per MMBTU [Member] Basis Swap Contracts for April Through December 2014 [Member]	Feb. 20, 2014 Basis Index Swaps [Member] Basis Swap Contracts for March 2014 [Member]	Feb. 20, 2014 Basis Index Swaps [Member] Basis Swap Contracts for April Through October 2014 [Member]	Feb. 20, 2014 Basis Index Swaps [Member] Basis Swap Contracts for April Through December 2014 [Member]	Feb. 20, 2014 Basis Index Swap contracts, price per MMBTU [Member] Basis Swap Contracts for March 2014 [Member]	Feb. 20, 2014 Basis Index Swap contracts, price per MMBTU [Member] Basis Swap Contracts for April Through October 2014 [Member]	Feb. 20, 2014 Basis Index Swap contracts, price per MMBTU [Member] Basis Swap Contracts for April Through December 2014 [Member]	Dec. 31, 2013 July 15, 2022 Interest Rate Swaps [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative, Nonmonetary Notional Amount			5,000	5,000	69,000					1,000	3,000	1,000	2,000						115,000	35,000				20,000	10,000	30,000
Derivative, Swap Type, Average Fixed Price																							(0.27)
Derivative, Average Cap Price								114.05						109.50		13.72					4.70
Derivative, Average Floor Price								93.70						95.00							4.00
Derivative, Notional Amount, Price Per Unit						0.82	0.60		77.61						80.00	10.78	47.57	48.51				3.00
Swap Multiple Second Nearby Month		0.6667
Swap Multiple Third Nearby Month		0.3333
Average Daily Index Swaps Price Differential																											0.34	0.36	0.30
Derivative fixed interest rate	3.21%																													3.95%
Derivative fixed interest rate term, years	10
Notional amount of debt	$ 250,000,000																													$ 400,000,000
Proceeds from Termination of Interest Rate Derivatives	$ 482,000
Derivative, Variable Interest Rate																														1.11%