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v3.19.1

Other liabilities - Stock Options (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2018 USD ($) shares | Dec. 31, 2017 Option USD ($)
Disclosure of terms and conditions of share-based payment arrangement [line items] |  |
Exercised during the period | Option |  | 30,000
Ferroglobe PLC Equity Incentive Plan [Member] |  |
Disclosure of terms and conditions of share-based payment arrangement [line items] |  |
Outstanding at beginning of the period | 757,365 | 264,933
Granted during the period | 485,860 | 492,432
Expired/forfeited during the period | shares | (218,183) |
Outstanding at end of the period | 1,025,042 | 757,365

X
- Definition The number of share options expired or forfeited in a share-based payment arrangement. + References No definition available. + Details
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- 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
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- Definition The number of share options outstanding in a share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_d&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause i -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_i&doctype=Standard -URIDate 2018-03-16 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause vi -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_vi&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The number of share options exercised in a share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause iv -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_iv&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The number of share options granted in a share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause ii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_ii&doctype=Standard -URIDate 2018-03-16 + Details
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- Details
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