XML 116 R99.htm IDEA: XBRL DOCUMENT
v3.19.1

Provisions (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | --- | ---
Disclosure of other provisions [line items] |  |  |
Non-current provisions | $ 75,787 | $ 82,397 |
Current provisions | 40,570 | 33,095 |
Provisions | 116,357 | 115,492 | $ 101,584
Provisions For Pensions [Member] |  |  |
Disclosure of other provisions [line items] |  |  |
Non-current provisions | 52,529 | 59,195 |
Current provisions | 197 |  |
Provisions | 52,726 | 59,195 | 60,876
Environment provision [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Non-current provisions | 2,880 | 3,121 |
Current provisions | 331 | 346 |
Provisions | 3,211 | 3,467 | 3,083
Provisions for litigation [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Current provisions | 2,399 | 11,732 |
Provisions | 2,399 | 11,732 |
Provisions for third-party liability [Member] |  |  |
Disclosure of other provisions [line items] |  |  |
Non-current provisions | 7,270 | 7,639 |
Current provisions | 7,270 | 7,639 |
Provisions | 7,270 | 7,639 | 5,835
Provisions for C02 emissions allowances [Member] |  |  |
Disclosure of other provisions [line items] |  |  |
Non-current provisions | 2,859 |  |
Current provisions | 25,111 | 7,281 |
Provisions | 27,970 | 7,281 | 5,512
Other provisions [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Non-current provisions | 10,249 | 12,442 |
Current provisions | 12,532 | 13,736 |
Provisions | 22,781 | 26,178 | $ 26,278
Environmental rehabilitation [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Non-current provisions | 2,880 | 3,121 |
Current provisions | 331 | 0 |
Provisions for litigation - FerroPem France [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Current provisions | 1,775 | 2,339 |
Other provisions, provisions for taxes [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Current provisions | 7,323 | 8,136 |
Other provisions, other [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Current provisions | $ 15,458 | $ 18,042 |

X
- Definition The amount of current provisions. [Refer: Provisions] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 54 -Subparagraph l -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_54_l&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_CurrentProvisions
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfOtherProvisionsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of non-current provisions. [Refer: Provisions] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 54 -Subparagraph l -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_54_l&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_NoncurrentProvisions
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of liabilities of uncertain timing or amount. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 54 -Subparagraph l -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_54_l&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_Provisions
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=gsm_ProvisionsForPensionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=ifrs-full_OtherEnvironmentRelatedProvisionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=ifrs-full_LegalProceedingsProvisionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=gsm_ProvisionsForThirdPartyLiabilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=gsm_ProvisionsForCo2EmissionsAllowancesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=ifrs-full_MiscellaneousOtherProvisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=gsm_EnvironmentalRehabilitationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=gsm_ProvisionsForLitigationFerropemFranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=gsm_OtherProvisionsProvisionsForTaxesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=gsm_OtherProvisionsOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |