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Supplemental Information on Oil and Natural Gas Producing Activities (Unaudited) - Estimate of Changes in Standardized Measure of Discounted Future Net Cash Flows from Proved Reserves (Unaudited) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2016 | Oct. 01, 2016 | Dec. 31, 2018 | Dec. 31, 2017
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward] |  |  |  |
Beginning present value |  |  | $ 749,294 | $ 438,364
Changes during the year |  |  |  |
Ending present value(2) | $ 438,364 |  | 1,045,603 | 749,294
Successor |  |  |  |
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward] |  |  |  |
Beginning present value | 392,604 |  | 749,294 | 438,364
Changes during the year |  |  |  |
Adoption of ASU 2015-02 | 0 |  | 0 | 0
Revenues less production | (70,668) |  | (236,553) | (239,838)
Net changes in prices, production and other costs | 35,684 |  | 316,095 | 347,458
Development costs incurred | 7,941 |  | 80,050 | 35,517
Net changes in future development costs | (291,232) |  | (11,483) | (64,484)
Extensions and discoveries | 14,986 |  | 102,961 | 112,556
Revisions of previous quantity estimates | 308,374 |  | (91,038) | 26,697
Accretion of discount | 9,375 |  | 70,576 | 37,226
Net change in income taxes | 0 |  | 56 | 23
Purchases of reserves in-place | 0 |  | 35,713 | 454
Sales of reserves in-place | 0 |  | (2,029) | (2,977)
Timing differences and other | 31,300 |  | 31,961 | 58,298
Net change for the year | 45,760 |  | 296,309 | 310,930
Ending present value(2) | 438,364 | $ 392,604 | $ 1,045,603 | $ 749,294
Predecessor |  |  |  |
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward] |  |  |  |
Beginning present value | $ 392,604 | 1,314,562 |  |
Changes during the year |  |  |  |
Adoption of ASU 2015-02 |  | (224,965) |  |
Revenues less production |  | (144,256) |  |
Net changes in prices, production and other costs |  | (394,173) |  |
Development costs incurred |  | 69,080 |  |
Net changes in future development costs |  | 436,041 |  |
Extensions and discoveries |  | 12,449 |  |
Revisions of previous quantity estimates |  | (728,254) |  |
Accretion of discount |  | 91,337 |  |
Net change in income taxes |  | 402 |  |
Purchases of reserves in-place |  | 0 |  |
Sales of reserves in-place |  | (13,314) |  |
Timing differences and other |  | (26,305) |  |
Net change for the year |  | (921,958) |  |
Ending present value(2) |  | $ 392,604 |  |

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- Definition Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of extensions, discoveries and improved recovery of proved oil and gas reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Form 20-F -Section Item 18 -Subsection Instruction 2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 35A -URI http://asc.fasb.org/extlink&oid=68064819&loc=SL6807758-109447 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=34713648&loc=d3e63123-109448 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 35 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62500-109447 + Details
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