Derivative Activities - Effects of Derivatives on Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2019 |
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Derivative [Line Items] | |||||||||||
| Derivative Fair Value (Loss) Income | $ 18,491 | $ 74,676 | $ 195,245 | $ (61,731) | $ 100,698 | $ (34,591) | $ (103,290) | $ (14,009) | $ 226,681 | $ (51,192) | $ 213,350 |
| Swaptions | |||||||||||
| Derivative [Line Items] | |||||||||||
| Derivative Fair Value (Loss) Income | 333 | (6,556) | 6,534 | ||||||||
| Collars | |||||||||||
| Derivative [Line Items] | |||||||||||
| Derivative Fair Value (Loss) Income | (3,903) | 17,583 | 18,132 | ||||||||
| Basis Swaps | |||||||||||
| Derivative [Line Items] | |||||||||||
| Derivative Fair Value (Loss) Income | 6,661 | (1,104) | (4,647) | ||||||||
| Puts | |||||||||||
| Derivative [Line Items] | |||||||||||
| Derivative Fair Value (Loss) Income | 0 | 0 | 10,929 | ||||||||
| Calls | |||||||||||
| Derivative [Line Items] | |||||||||||
| Derivative Fair Value (Loss) Income | (349) | (2,653) | 987 | ||||||||
| Commodity | Swaps | |||||||||||
| Derivative [Line Items] | |||||||||||
| Derivative Fair Value (Loss) Income | 219,968 | (57,950) | 181,095 | ||||||||
| Freight | Swaps | |||||||||||
| Derivative [Line Items] | |||||||||||
| Derivative Fair Value (Loss) Income | $ 3,971 | $ (512) | $ 320 | ||||||||