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Derivative Instruments - Schedule of Outstanding Commodity Derivative Instruments (Details) $ in Thousands | 1 Months Ended | 9 Months Ended
--- | --- | ---
Oct. 31, 2018 MMBTU $ / bbl $ / MMBTU bbl | Sep. 30, 2018 USD ($) MMBTU $ / bbl $ / MMBTU bbl
Derivative [Line Items] |  |
Fair value asset | $ |  | $ (213,146)
Crude Oil [Member] | 2018 Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 3,761,000
Average swap price (in dollars per barrel) |  | 52.95
Fair value asset | $ |  | $ (71,621)
Crude Oil [Member] | 2018 Basis Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 152,000
Average swap price (in dollars per barrel) |  | 9.84
Fair value asset | $ |  | $ 81
Crude Oil [Member] | 2018 Two-way Collars [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 517,000
Average floor price (in dollars per barrel) |  | 58.74
Average ceiling price (in dollars per barrel) |  | 63.94
Fair value asset | $ |  | $ (5,171)
Crude Oil [Member] | 2019 Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 5,613,000
Average swap price (in dollars per barrel) |  | 53.33
Fair value asset | $ |  | $ (99,347)
Crude Oil [Member] | 2019 Basis Swaps [Member] [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 424,000
Average swap price (in dollars per barrel) |  | 9.68
Fair value asset | $ |  | $ 408
Crude Oil [Member] | 2019 Two-way Collars [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 3,223,000
Average floor price (in dollars per barrel) |  | 57.99
Average ceiling price (in dollars per barrel) |  | 75.46
Fair value asset | $ |  | $ (7,580)
Crude Oil [Member] | 2019 Three-way Collars [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 3,368,000
Average sub-floor price (in dollars per barrel) |  | 40.54
Average floor price (in dollars per barrel) |  | 51.03
Average ceiling price (in dollars per barrel) |  | 68.68
Fair value asset | $ |  | $ (21,771)
Crude Oil [Member] | 2020 Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 403,000
Average swap price (in dollars per barrel) |  | 53.47
Fair value asset | $ |  | $ (5,911)
Crude Oil [Member] | 2020 Two-way Collars [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 279,000
Average floor price (in dollars per barrel) |  | 57.78
Average ceiling price (in dollars per barrel) |  | 76.13
Fair value asset | $ |  | $ (273)
Crude Oil [Member] | 2020 Three-way Collars [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl |  | 279,000
Average sub-floor price (in dollars per barrel) |  | 40.00
Average floor price (in dollars per barrel) |  | 50.56
Average ceiling price (in dollars per barrel) |  | 67.80
Fair value asset | $ |  | $ (1,778)
Natural Gas [Member] | 2018 Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU |  | 3,496,000
Average swap price (in dollars per barrel) | $ / MMBTU |  | 3.01
Fair value asset | $ |  | $ (104)
Natural Gas [Member] | 2018 Basis Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU |  | 1,225,000
Average swap price (in dollars per barrel) |  | 0.05
Fair value asset | $ |  | $ (64)
Natural Gas [Member] | 2019 Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU |  | 1,896,000
Average swap price (in dollars per barrel) | $ / MMBTU |  | 2.95
Fair value asset | $ |  | $ 16
Natural Gas [Member] | 2019 Basis Swaps [Member] [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU |  | 2,715,000
Average swap price (in dollars per barrel) |  | 0.05
Fair value asset | $ |  | $ (31)
Subsequent Event [Member] | Crude Oil [Member] |  |
Derivative [Line Items] |  |
Average floor price (in dollars per barrel) | 64.05 |
Addition (reduction) in weighted average differential prices | (7.50) |
Subsequent Event [Member] | Crude Oil [Member] | 2018 Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl | 213,000 |
Subsequent Event [Member] | Crude Oil [Member] | 2018 Basis Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU | 60,000 |
Subsequent Event [Member] | Crude Oil [Member] | 2019 Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl | 792,000 |
Subsequent Event [Member] | Crude Oil [Member] | 2019 Basis Swaps [Member] [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU | 424,000 |
Subsequent Event [Member] | Crude Oil [Member] | 2020 Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of oil (in Bbls) | bbl | 62,000 |
Subsequent Event [Member] | Natural Gas [Member] |  |
Derivative [Line Items] |  |
Average floor price (in dollars per barrel) | $ / MMBTU | 2.88 |
Addition (reduction) in weighted average differential prices | $ / MMBTU | 0.13 |
Subsequent Event [Member] | Natural Gas [Member] | 2018 Basis Swaps [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU | 610,000 |
Subsequent Event [Member] | Natural Gas [Member] | 2018 Two-way Collars [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU | 305,000 |
Subsequent Event [Member] | Natural Gas [Member] | 2019 Basis Swaps [Member] [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU | 1,810,000 |
Subsequent Event [Member] | Natural Gas [Member] | 2019 Two-way Collars [Member] |  |
Derivative [Line Items] |  |
Total notional amount of natural gas (in MMBtu) | MMBTU | 1,825,000 |

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