Fair value measurements (Level 3 Rollforward) (Detail) - Recurring Fair Value Measurements - Significant Unobservable Inputs (Level 3) - Derivative - USD ($)
$ in Thousands |
|
3 Months Ended |
12 Months Ended |
Mar. 31, 2017 |
Mar. 21, 2017 |
Mar. 31, 2016 |
Dec. 31, 2016 |
Dec. 31, 2015 |
| Level 3 Rollforward |
|
|
|
|
|
| Beginning balance |
$ 715
|
|
|
|
|
| Realized and unrealized (losses) gains included in derivative gains |
(239)
|
|
|
|
|
| Settlements received |
0
|
|
|
|
|
| Ending balance |
476
|
$ 715
|
|
|
|
| (Losses) gains relating to instruments still held at the reporting date included in derivative (losses) gains for the period |
(239)
|
|
|
|
|
| Predecessor |
|
|
|
|
|
| Level 3 Rollforward |
|
|
|
|
|
| Beginning balance |
$ 715
|
(98)
|
$ 123,068
|
$ 123,068
|
$ 195,167
|
| Realized and unrealized (losses) gains included in derivative gains |
|
813
|
6,978
|
(9,314)
|
105,055
|
| Purchases |
|
|
|
0
|
0
|
| Settlements received |
|
0
|
(39,093)
|
(113,852)
|
(177,154)
|
| Ending balance |
|
715
|
90,953
|
(98)
|
123,068
|
| (Losses) gains relating to instruments still held at the reporting date included in derivative (losses) gains for the period |
|
$ 813
|
$ 2,027
|
$ (98)
|
$ 61,260
|