Derivative Instruments and Hedging Activities (Details)	Sep. 30, 2017 bbl / d $ / shares $ / bbl
Crude Oil Contract | Call Option - NYMEX WTI Second Half of 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	3,000
Crude Oil Contract | Three Way Collars - ICE Brent Second Half of 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	5,000
Crude Oil Contract | Three Way Collars - NYMEX WTI 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	24,000
Crude Oil Contract | Two Way Collars - NYMEX WTI 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	10,804
Crude Oil Contract | Swaps - NYMEX WTI 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	4,293
Crude Oil Contract | Call Option - NYMEX WTI 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	3,000
Crude Oil Contract | Three Way Collars - ICE Brent 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	2,000
Crude Oil Contract | Three Way Collars - Dated Brent 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	2,000
Crude Oil Contract | Three Way Collars - NYMEX WTI 2018
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	10,000
Crude Oil Contract | Three Way Collars - Dated Brent 2018
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	3,000
Crude Oil Contract | Swaptions - NYMEX WTI 2018
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	3,000
Crude Oil Contract | Three Way Collars - ICE Brent 2018
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	5,000
Crude Oil Contract | Two Way Collars - ICE Brent 2018
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	2,000
Crude Oil Contract | Basic Swap 2018
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	8,000
Crude Oil Contract | Three Way Collar - ICE Brent 2019
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	3,000
Crude Oil Contract | Basic Swap 2019
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	12,000
Natural Gas Contract | Three Way Collars - NYMEX HH 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	110,000
Weighted Average Fixed Price ($ per bbl)	0.00
Weighted Average Short Put Price ($ per bbl)	2.58
Weighted Average Floor Price ($ per bbl)	2.93
Weighted Average Ceiling Price ($ per bbl)	3.65
Natural Gas Contract | Two Way Collars - NYMEX HH 2017
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	70,000
Weighted Average Fixed Price ($ per bbl)	0.00
Weighted Average Short Put Price ($ per bbl)	0.00
Weighted Average Floor Price ($ per bbl)	2.93
Weighted Average Ceiling Price ($ per bbl)	3.32
Natural Gas Contract | Three Way Collars - NYMEX HH 2018
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	120,000
Weighted Average Fixed Price ($ per bbl)	0.00
Weighted Average Short Put Price ($ per bbl)	2.50
Weighted Average Floor Price ($ per bbl)	2.88
Weighted Average Ceiling Price ($ per bbl)	3.65
Natural Gas Contract | Swaptions - NYMEX HH 2018
Derivative [Line Items]
Bbls Per Day (Bbls per day) | bbl / d	30,000
Weighted Average Fixed Price ($ per bbl)	3.36
Weighted Average Short Put Price ($ per bbl)	0.00
Weighted Average Floor Price ($ per bbl)	0.00
Weighted Average Ceiling Price ($ per bbl)	0.00
Swaps | Crude Oil Contract | Swaps - NYMEX WTI 2017
Derivative [Line Items]
Weighted Average Fixed Price ($ per bbl)	50.84
Swaps | Crude Oil Contract | Swaptions - NYMEX WTI 2018
Derivative [Line Items]
Weighted Average Fixed Price ($ per bbl)	56.10
Swaps | Crude Oil Contract | Basic Swap 2018
Derivative [Line Items]
Weighted Average Differential ($ per bbl) | $ / shares	$ (0.78)
Swaps | Crude Oil Contract | Basic Swap 2019
Derivative [Line Items]
Weighted Average Differential ($ per bbl) | $ / shares	$ (1.01)
Collars | Crude Oil Contract | Call Option - NYMEX WTI Second Half of 2017
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	0.00
Weighted Average Floor Price ($ per bbl)	0.00
Weighted Average Ceiling Price ($ per bbl)	60.12
Collars | Crude Oil Contract | Three Way Collars - ICE Brent Second Half of 2017
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	43.00
Weighted Average Floor Price ($ per bbl)	50.00
Weighted Average Ceiling Price ($ per bbl)	64.00
Collars | Crude Oil Contract | Three Way Collars - NYMEX WTI 2017
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	39.08
Weighted Average Floor Price ($ per bbl)	47.71
Weighted Average Ceiling Price ($ per bbl)	61.20
Collars | Crude Oil Contract | Two Way Collars - NYMEX WTI 2017
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	0.00
Weighted Average Floor Price ($ per bbl)	40.80
Weighted Average Ceiling Price ($ per bbl)	52.72
Collars | Crude Oil Contract | Call Option - NYMEX WTI 2017
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	0.00
Weighted Average Floor Price ($ per bbl)	0.00
Weighted Average Ceiling Price ($ per bbl)	57.00
Collars | Crude Oil Contract | Three Way Collars - ICE Brent 2017
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	43.00
Weighted Average Floor Price ($ per bbl)	50.00
Weighted Average Ceiling Price ($ per bbl)	63.15
Collars | Crude Oil Contract | Three Way Collars - Dated Brent 2017
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	35.00
Weighted Average Floor Price ($ per bbl)	45.00
Weighted Average Ceiling Price ($ per bbl)	66.33
Collars | Crude Oil Contract | Three Way Collars - NYMEX WTI 2018
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	45.50
Weighted Average Floor Price ($ per bbl)	52.50
Weighted Average Ceiling Price ($ per bbl)	69.09
Collars | Crude Oil Contract | Three Way Collars - Dated Brent 2018
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	40.00
Weighted Average Floor Price ($ per bbl)	50.00
Weighted Average Ceiling Price ($ per bbl)	70.41
Collars | Crude Oil Contract | Three Way Collars - ICE Brent 2018
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	43.00
Weighted Average Floor Price ($ per bbl)	50.00
Weighted Average Ceiling Price ($ per bbl)	59.50
Collars | Crude Oil Contract | Two Way Collars - ICE Brent 2018
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	0.00
Weighted Average Floor Price ($ per bbl)	50.00
Weighted Average Ceiling Price ($ per bbl)	55.25
Collars | Crude Oil Contract | Three Way Collar - ICE Brent 2019
Derivative [Line Items]
Weighted Average Short Put Price ($ per bbl)	43.00
Weighted Average Floor Price ($ per bbl)	50.00
Weighted Average Ceiling Price ($ per bbl)	64.07