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Fair value measurements and derivative instruments - Schedule of realized (gains) losses on derivatives recognized In statement of operations (Details) - USD ($) $ in Thousands | 5 Months Ended | 7 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2015 | Aug. 14, 2015 | Dec. 31, 2017 | Dec. 31, 2016
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency derivatives | Cost Of Good Sold Other Expense Income Revenue [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Amount of (Gain)/Loss Recognized | $ (172) |  |  | $ (322)
Derivative, Gain (loss) on derivative, tax | 17 |  | $ 0 | 32
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency derivatives | Cost Of Good Sold Other Expense Income Revenue [Member] | Predecessor [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Amount of (Gain)/Loss Recognized |  | $ (1,062) |  |
Derivative, Gain (loss) on derivative, tax |  | 106 |  |
Designated as Hedging Instrument | Cash Flow Hedging | Commodity Forward Derivatives [Member] | Cost of Sales [Member] | Predecessor [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Amount of (Gain)/Loss Recognized |  | 1,161 |  |
Derivative, Gain (loss) on derivative, tax |  | 424 |  |
Not Designated as Hedging Instrument [Member] | Foreign currency derivatives | Cost Of Good Sold Other Expense Income Revenue [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Amount of (Gain)/Loss Recognized | $ (560) |  | $ (1,565) | $ 549
Not Designated as Hedging Instrument [Member] | Foreign currency derivatives | Cost Of Good Sold Other Expense Income Revenue [Member] | Predecessor [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Amount of (Gain)/Loss Recognized |  | $ 1,060 |  |

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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
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