Derivatives and Financial Instruments - Summary of Open Derivative Contracts for Oil and Natural Gas (Details) - Not Designated as Hedging Instrument		6 Months Ended
	Aug. 13, 2015 MMBTU $ / bbl $ / MMBTU bbl	Jun. 30, 2015 MMBTU $ / bbl $ / MMBTU bbl
Oil | Q2 2015 | 2015 Collar Contracts | Call Options
Derivative [Line Items]
Derivative Contract, Volume | bbl		92,000
Derivative Contract, Weighted Average Price		102.73
Derivative Contract, Price Range Low		101.00
Derivative Contract, Price Range High		104.00
Oil | Q2 2015 | 2015 Collar Contracts | Put Options
Derivative [Line Items]
Derivative Contract, Volume | bbl		92,000
Derivative Contract, Weighted Average Price		86.14
Derivative Contract, Price Range Low		84.00
Derivative Contract, Price Range High		90.00
Oil | Q2 2015 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | bbl		108,000
Derivative Contract, Weighted Average Price		57.69
Derivative Contract, Price Range Low		55.60
Derivative Contract, Price Range High		58.77
Oil | Q3 2015 | 2015 Collar Contracts | Call Options
Derivative [Line Items]
Derivative Contract, Volume | bbl		161,000
Derivative Contract, Weighted Average Price		102.45
Derivative Contract, Price Range Low		102.00
Derivative Contract, Price Range High		103.55
Oil | Q3 2015 | 2015 Collar Contracts | Put Options
Derivative [Line Items]
Derivative Contract, Volume | bbl		161,000
Derivative Contract, Weighted Average Price		84.88
Derivative Contract, Price Range Low		84.00
Derivative Contract, Price Range High		87.00
Oil | Q3 2015 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | bbl		405,000
Derivative Contract, Weighted Average Price		58.99
Derivative Contract, Price Range Low		56.76
Derivative Contract, Price Range High		60.22
Oil | Q3 2015 | Swap Contracts | Swap | Subsequent Events
Derivative [Line Items]
Derivative Contract, Volume | bbl	20,000
Derivative Contract, Weighted Average Price	46.88
Derivative Contract, Price Range Low	46.86
Derivative Contract, Price Range High	46.90
Oil | Q4 2015 | 2015 Collar Contracts | Call Options
Derivative [Line Items]
Derivative Contract, Volume | bbl		30,000
Derivative Contract, Weighted Average Price		102.00
Derivative Contract, Price Range Low		102.00
Derivative Contract, Price Range High		102.00
Oil | Q4 2015 | 2015 Collar Contracts | Put Options
Derivative [Line Items]
Derivative Contract, Volume | bbl		30,000
Derivative Contract, Weighted Average Price		85.00
Derivative Contract, Price Range Low		85.00
Derivative Contract, Price Range High		85.00
Oil | Q4 2015 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | bbl		471,000
Derivative Contract, Weighted Average Price		60.60
Derivative Contract, Price Range Low		59.00
Derivative Contract, Price Range High		61.71
Oil | Q4 2015 | Swap Contracts | Swap | Subsequent Events
Derivative [Line Items]
Derivative Contract, Volume | bbl	60,000
Derivative Contract, Weighted Average Price	48.13
Derivative Contract, Price Range Low	47.39
Derivative Contract, Price Range High	49.18
Oil | 2016 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | bbl		1,638,000
Derivative Contract, Weighted Average Price		58.21
Derivative Contract, Price Range Low		54.80
Derivative Contract, Price Range High		63.07
Oil | 2016 | Swap Contracts | Swap | Subsequent Events
Derivative [Line Items]
Derivative Contract, Volume | bbl	141,000
Derivative Contract, Weighted Average Price	50.95
Derivative Contract, Price Range Low	48.54
Derivative Contract, Price Range High	53.30
Oil | 2017 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | bbl		343,000
Derivative Contract, Weighted Average Price		63.28
Derivative Contract, Price Range Low		62.87
Derivative Contract, Price Range High		63.65
Oil | 2017 | Swap Contracts | Swap | Subsequent Events
Derivative [Line Items]
Derivative Contract, Volume | bbl	360,000
Derivative Contract, Weighted Average Price	53.95
Derivative Contract, Price Range Low	52.73
Derivative Contract, Price Range High	54.38
Natural Gas | Q3 2015 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | MMBTU		7,590,000
Derivative Contract, Weighted Average Price | $ / MMBTU		3.09
Derivative Contract, Price Range Low | $ / MMBTU		2.84
Derivative Contract, Price Range High | $ / MMBTU		3.22
Natural Gas | Q3 2015 | Swap Contracts | Swap | Subsequent Events
Derivative [Line Items]
Derivative Contract, Volume | MMBTU	280,000
Derivative Contract, Weighted Average Price | $ / MMBTU	2.80
Derivative Contract, Price Range Low | $ / MMBTU	2.80
Derivative Contract, Price Range High | $ / MMBTU	2.80
Natural Gas | Q4 2015 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | MMBTU		6,900,000
Derivative Contract, Weighted Average Price | $ / MMBTU		3.25
Derivative Contract, Price Range Low | $ / MMBTU		2.88
Derivative Contract, Price Range High | $ / MMBTU		3.53
Natural Gas | Q4 2015 | Swap Contracts | Swap | Subsequent Events
Derivative [Line Items]
Derivative Contract, Volume | MMBTU	700,000
Derivative Contract, Weighted Average Price | $ / MMBTU	2.94
Derivative Contract, Price Range Low | $ / MMBTU	2.82
Derivative Contract, Price Range High | $ / MMBTU	3.11
Natural Gas | 2016 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | MMBTU		22,940,000
Derivative Contract, Weighted Average Price | $ / MMBTU		3.18
Derivative Contract, Price Range Low | $ / MMBTU		3.03
Derivative Contract, Price Range High | $ / MMBTU		3.41
Natural Gas | 2016 | Swap Contracts | Swap | Subsequent Events
Derivative [Line Items]
Derivative Contract, Volume | MMBTU	1,310,000
Derivative Contract, Weighted Average Price | $ / MMBTU	3.12
Derivative Contract, Price Range Low | $ / MMBTU	3.00
Derivative Contract, Price Range High | $ / MMBTU	3.35
Natural Gas | 2017 | Swap Contracts | Swap
Derivative [Line Items]
Derivative Contract, Volume | MMBTU		4,640,000
Derivative Contract, Weighted Average Price | $ / MMBTU		3.49
Derivative Contract, Price Range Low | $ / MMBTU		3.43
Derivative Contract, Price Range High | $ / MMBTU		3.52
Natural Gas | 2017 | Swap Contracts | Swap | Subsequent Events
Derivative [Line Items]
Derivative Contract, Volume | MMBTU	5,010,000
Derivative Contract, Weighted Average Price | $ / MMBTU	3.18
Derivative Contract, Price Range Low | $ / MMBTU	3.14
Derivative Contract, Price Range High | $ / MMBTU	3.46