XML 59 R42.htm IDEA: XBRL DOCUMENT
v3.19.1

Goodwill (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2018
Disclosure of reconciliation of changes in goodwill [abstract] |
Schedule of changes in the carrying amount of goodwill |
|  | January 1, |  | Impairment |  | Exchange |  | December 31, |  | Impairment |  | Exchange |  | December 31,
|  | 2017 |  | (Note 25.5) |  | differences |  | 2017 |  | (Note 25.5) |  | differences |  | 2018
|  | US$'000 |  | US$'000 |  | US$'000 |  | US$'000 |  | US$'000 |  | US$'000 |  | US$'000
Globe Specially Metals, Inc. (Globe) |  | 230,210 |  | (30,618) |  | 5,695 |  | 205,287 |  | — |  | (2,439) |  | 202,848
Total |  | 230,210 |  | (30,618) |  | 5,695 |  | 205,287 |  | — |  | (2,439) |  | 202,848
Schedule of key assumptions used in the determination of recoverable value |
|  | 2018 |  |  | 2017 |
|  | U.S. |  | Canada |  |  | U.S. |  | Canada |
Weighted average cost of capital |  | 11.0 | % | 10.5 | % |  | 10.5 | % | 10.5 | %
Long-term growth rate |  | 2.0 | % | 2.0 | % |  | 1.5 | % | 1.5 | %
Normalized tax rate |  | 22.0 | % | 26.5 | % |  | 27.1 | % | 26.5 | %
Normalized cash free net working capital |  | 21.0 | % | 21.0 | % |  | 21.0 | % | 21.0 | %
Schedule of sensitivity to changes in assumptions affecting impairment |
|  |  |  | Excess of |  | Sensitivity on |  | Sensitivity on |  | Sensitivity on
|  |  |  | recoverable |  | discount rate |  | long-term growth rate |  | cash flows
|  |  |  | value over |  | Decrease |  | Increase |  | Decrease |  | Increase |  | Decrease |  | Increase
|  | Goodwill |  | carrying value |  | by 10% |  | by 10% |  | by 10% |  | by 10% |  | by 10% |  | by 10%
|  | (in millions of US$)
Electrometallurgy - U.S. |  | 172.9 |  | 43.2 |  | 94.4 |  | (73.7) |  | (11.0) |  | 11.5 |  | (59.7) |  | 59.7
Electrometallurgy - Canada |  | 29.9 |  | 4.8 |  | 17.7 |  | (13.8) |  | (2.2) |  | 2.3 |  | (12.1) |  | 12.1
Total |  | 202.8 |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition The disclosure of key assumptions used in the determination of recoverable value of business acquisitions. + References No definition available. + Details
Name: | gsm_DisclosureOfAssumptionsUsedInDeterminationOfRecoverableValueOfBusinessAcquisitionsTableTextBlock
Namespace Prefix: | gsm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition The disclosure of sensitivity to changes in assumptions used to determine impairment. + References No definition available. + Details
Name: | gsm_DisclosureOfSensitivityToChangesInAssumptionsUsedToDetermineImpairmentTableTextBlock
Namespace Prefix: | gsm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | ifrs-full_DisclosureOfReconciliationOfChangesInGoodwillAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The disclosure of the reconciliation of changes in goodwill. [Refer: Goodwill] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 3 -IssueDate 2018-01-01 -Paragraph B67 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=3&date=2018-03-01&anchor=para_B67_d&doctype=Appendix&seq=2 -URIDate 2018-03-16 + Details
Name: | ifrs-full_DisclosureOfReconciliationOfChangesInGoodwillExplanatory
Namespace Prefix: | ifrs-full_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration