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Income taxes- Income Tax Expense (Benefit) Computed By Applying The U.S. Federal Income Tax Rate (Details) - USD ($) $ in Thousands | 5 Months Ended | 6 Months Ended | 7 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Dec. 31, 2015 | Jun. 30, 2018 | Jun. 30, 2017 | Aug. 14, 2015 | Dec. 31, 2017 | Dec. 31, 2016
Income taxes |  |  |  |  |  |
Tax at statutory U.S. federal rate | $ (7,610) |  |  |  | $ 1,201 | $ (40,747)
U.S. valuation allowance, net | 7,355 |  |  |  | (89,269) | 35,091
State taxes, net of federal tax benefit | (697) |  |  |  | 3,437 | (2,324)
Impact of the 2017 Tax Act-transition tax |  |  |  |  | 39,628 |
Impact of the 2017 Tax Act-tax rate change |  |  |  |  | 52,228 |
U.S. tax return adjustments to estimated taxes | 139 |  |  |  | 1,151 | 51
Resolution of uncertain tax positions | 64 |  |  |  | (840) | (513)
Adjustment for foreign income taxed at different rates | 7,120 |  |  |  | (2,359) | 12,738
Foreign tax credits |  |  |  |  | (18,244) |
Non-U.S. tax exemptions, holidays and credits | 228 |  |  |  | 288 | (175)
Goodwill impairment |  |  |  |  | 700 |
Investment in subsidiary impairment deduction |  |  |  |  |  | (10,114)
Other | 283 |  |  |  | 1,299 | (1,562)
Income Tax Expense (Benefit), Total | $ 6,882 | $ 11,379 | $ 1,286 |  | $ (10,781) | $ (7,552)
Predecessor [Member] |  |  |  |  |  |
Income taxes |  |  |  |  |  |
Tax at statutory U.S. federal rate |  |  |  | $ (33,431) |  |
U.S. valuation allowance, net |  |  |  | 21,532 |  |
State taxes, net of federal tax benefit |  |  |  | (2,005) |  |
Resolution of uncertain tax positions |  |  |  | 71 |  |
Adjustment for foreign income taxed at different rates |  |  |  | 11,136 |  |
Non-U.S. tax exemptions, holidays and credits |  |  |  | (691) |  |
Goodwill impairment |  |  |  | 8,026 |  |
Other |  |  |  | 1,814 |  |
Income Tax Expense (Benefit), Total |  |  |  | $ 6,452 |  |

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- Definition Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to increase (decrease) in income tax rate and transition tax on accumulated earnings of controlled foreign corporation deemed repatriated pursuant to Tax Cuts and Jobs Act of 2017. + References No definition available. + Details
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
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