Derivative Instruments and Hedging Activities (Details) - Jun. 30, 2015		bbl / d MMBTU / d $ / bbl $ / MMBTU
Crude Oil Commodity Contract | Swaps - NYMEX WTI 2015
Derivative [Line Items]
Settlement Period		2015
Index		NYMEX WTI
Bbls Per Day | bbl / d		27,000
Weighted Average Fixed Price		88.80
Crude Oil Commodity Contract | Swaps - Dated Brent 2015
Derivative [Line Items]
Settlement Period		2015
Index		Dated Brent
Bbls Per Day | bbl / d		8,000
Weighted Average Fixed Price		100.31
Crude Oil Commodity Contract | Two Way Collars - NYMEX WTI 2015
Derivative [Line Items]
Settlement Period		2015
Index		NYMEX WTI
Bbls Per Day | bbl / d		5,000
Weighted Average Floor Price		50.00
Weighted Average Ceiling Price		64.94
Crude Oil Commodity Contract | Three Way Collars - NYMEX WTI 2015
Derivative [Line Items]
Settlement Period		2015
Index		NYMEX WTI
Bbls Per Day | bbl / d		20,000
Weighted Average Short Put Price		70.50
Weighted Average Floor Price		87.55
Weighted Average Ceiling Price		94.41
Crude Oil Commodity Contract | Three Way Collars - Dated Brent 2015
Derivative [Line Items]
Settlement Period		2015
Index		Dated Brent
Bbls Per Day | bbl / d		13,000
Weighted Average Short Put Price		76.92
Weighted Average Floor Price		96.00
Weighted Average Ceiling Price		108.49
Crude Oil Commodity Contract | Swaps - NYMEX WTI 2016
Derivative [Line Items]
Settlement Period		2016
Index		NYMEX WTI
Bbls Per Day | bbl / d		9,000
Weighted Average Fixed Price		80.30
Crude Oil Commodity Contract | Swaps - Dated Brent 2016
Derivative [Line Items]
Settlement Period		2016
Index		Dated Brent
Bbls Per Day | bbl / d		9,000
Weighted Average Fixed Price		97.96
Crude Oil Commodity Contract | Three Way Collars - NYMEX WTI 2016
Derivative [Line Items]
Settlement Period		2016
Index		NYMEX WTI
Bbls Per Day | bbl / d		6,000
Weighted Average Short Put Price		61.00
Weighted Average Floor Price		72.50
Weighted Average Ceiling Price		86.37
Crude Oil Commodity Contract | Three Way Collars - Dated Brent 2016
Derivative [Line Items]
Settlement Period		2016
Index		Dated Brent
Bbls Per Day | bbl / d		8,000
Weighted Average Short Put Price		72.50
Weighted Average Floor Price		86.25
Weighted Average Ceiling Price		101.79
Crude Oil Commodity Contract | Two Way Collars - NYMEX HH 2016
Derivative [Line Items]
Settlement Period		2016
Index		NYMEX WTI
Bbls Per Day | bbl / d		1,000
Weighted Average Floor Price		60.00
Weighted Average Ceiling Price		70.00
Natural Gas Commodity Contract | Swaps - NYMEX HH 2015
Derivative [Line Items]
Settlement Period		2015
Index		NYMEX HH
Bbls Per Day | MMBTU / d		140,000
Weighted Average Fixed Price | $ / MMBTU		4.30
Natural Gas Commodity Contract | Three Way Collars - NYMEX HH 2015
Derivative [Line Items]
Settlement Period		2015
Index		NYMEX HH
Bbls Per Day | MMBTU / d		150,000
Weighted Average Short Put Price | $ / MMBTU		3.58
Weighted Average Floor Price | $ / MMBTU		4.25
Weighted Average Ceiling Price | $ / MMBTU		5.04
Natural Gas Commodity Contract | Swaps - NYMEX HH 2016
Derivative [Line Items]
Settlement Period		2016
Index		NYMEX HH
Bbls Per Day | MMBTU / d	[1]	40,000
Weighted Average Fixed Price | $ / MMBTU	[1]	3.60
Natural Gas Commodity Contract | Two Way Collars - NYMEX HH 2016
Derivative [Line Items]
Settlement Period		2016
Index		NYMEX HH
Bbls Per Day | MMBTU / d		30,000
Weighted Average Floor Price | $ / MMBTU		3.00
Weighted Average Ceiling Price | $ / MMBTU		3.50
Natural Gas Commodity Contract | Three Way Collars - NYMEX HH 2016
Derivative [Line Items]
Settlement Period		2016
Index		NYMEX HH
Bbls Per Day | MMBTU / d		90,000
Weighted Average Short Put Price | $ / MMBTU		2.83
Weighted Average Floor Price | $ / MMBTU		3.42
Weighted Average Ceiling Price | $ / MMBTU		3.90
Natural Gas Commodity Contract | Swaps - NYMEX HH Extension
Derivative [Line Items]
Bbls Per Day | MMBTU / d		30,000
Natural Gas Commodity Contract | Swaps - NYMEX HH Increase
Derivative [Line Items]
Bbls Per Day | MMBTU / d		30,000
Weighted Average Fixed Price | $ / MMBTU	[1]	3.50

[1] (1) We have entered into natural gas derivative contracts which give counterparties the option to extend for an additional 12-month period. Options covering a notional volume of 30,000 MMBtu/d are exercisable on December 22 and 23, 2016. If the counterparties exercise all such options, the notional volume of our existing natural gas derivative contracts will increase by 30,000 MMBtu/d at an average price of $3.50 per MMBtu for each month during the period January 1, 2017 through December 31, 2017.