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Derivative Instruments - Schedule of Outstanding Commodity Derivative Instruments (Detail) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 USD ($) MMBTU $ / bbl $ / MMBTU bbl
Derivative [Line Items] |
Fair value asset (liability) | $ | $ (135,214)
Crude oil | 2018 Swaps |
Derivative [Line Items] |
Total notional amount of oil barrels (in bbl) | bbl | 13,675,000
Average swap price (in dollars per barrel / dollars per btu) | 51.25
Fair value asset (liability) | $ | $ (109,129)
Crude oil | 2018 Two-way Collar |
Derivative [Line Items] |
Total notional amount of oil barrels (in bbl) | bbl | 1,250,000
Average floor price (in dollars per barrel / dollars per btu) | 48.19
Average ceiling price (in dollars per barrel / dollars per btu) | 53.33
Fair value asset (liability) | $ | $ (7,785)
Crude oil | 2018 Three-way Collar |
Derivative [Line Items] |
Total notional amount of oil barrels (in bbl) | bbl | 186,000
Average sub-floor price (in dollars per barrel / dollars per btu) | 31.67
Average floor price (in dollars per barrel / dollars per btu) | 45.83
Average ceiling price (in dollars per barrel / dollars per btu) | 59.94
Fair value asset (liability) | $ | $ (107)
Crude oil | 2019 Swaps |
Derivative [Line Items] |
Total notional amount of oil barrels (in bbl) | bbl | 4,091,000
Average swap price (in dollars per barrel / dollars per btu) | 51.52
Fair value asset (liability) | $ | $ (18,635)
Crude oil | 2019 Two-way Collar |
Derivative [Line Items] |
Total notional amount of oil barrels (in bbl) | bbl | 93,000
Average floor price (in dollars per barrel / dollars per btu) | 48.67
Average ceiling price (in dollars per barrel / dollars per btu) | 53.07
Fair value asset (liability) | $ | $ (513)
Crude oil | 2020 Swaps |
Derivative [Line Items] |
Total notional amount of oil barrels (in bbl) | bbl | 279,000
Average swap price (in dollars per barrel / dollars per btu) | 51.76
Fair value asset (liability) | $ | $ (728)
Natural gas | 2018 Swaps |
Derivative [Line Items] |
Total notional amount of natural gas (in MMBtu) | MMBTU | 7,665,000
Average swap price (in dollars per barrel / dollars per btu) | $ / MMBTU | 3.05
Fair value asset (liability) | $ | $ 1,683

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