Derivatives Derivatives (Details 4-Non Hedges Commodity) (Details) - Jun. 30, 2015		BBL / Days $ / bbl
Three-Way Collars Jul-Dec15 [Member]
Derivative [Line Items]
Barrels per day (BBL per day) | BBL / Days	[1]	35,000
Price per barrel ceiling (usd per barrel)	[1]	70.34
Price per barrel floor (usd per barrel)	[1]	55.57
Price per barrel sold put (usd per barrel)	[1]	41.29
Three-Way Collars Jan-Dec16 [Member] [Member]
Derivative [Line Items]
Barrels per day (BBL per day) | BBL / Days		12,000
Price per barrel ceiling (usd per barrel)		71.84
Price per barrel floor (usd per barrel)		60.48
Price per barrel sold put (usd per barrel)		50.00
Three-Way Collars Jan-Jun16 [Member] [Member] [Member]
Derivative [Line Items]
Barrels per day (BBL per day) | BBL / Days	[2]	2,000
Price per barrel ceiling (usd per barrel)	[2]	73.13
Price per barrel floor (usd per barrel)	[2]	65.00
Price per barrel sold put (usd per barrel)	[2]	50.00
Call Options Jan-Dec16 [Member]
Derivative [Line Items]
Barrels per day (BBL per day) | BBL / Days	[3]	10,000
Derivative, Price Risk Option Strike Price	[3]	72.39
Swaption [Member]
Derivative [Line Items]
Barrels per day (BBL per day) | BBL / Days		25,000
Fixed-price swap (usd per barrel)		71.67

[1] Counterparties have the option to execute fixed-price swaps (swaptions) at a weighted average price of $71.67 per barrel indexed to NYMEX WTI, which is exercisable on October 30, 2015. If counterparties exercise, the term of the fixed price swaps would be for calendar year 2016 and, if all such are exercised, 25,000 barrels per day.

[2] Counterparty has the option, exercisable on June 30, 2016, to extend these collars through the remainder of 2016 at the same volume and weighted average price as the underlying three-way collars.

[3] Call options settle monthly.