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Assumption used to Value Shares (Detail) (ZAR) | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items] |  |
Weighted average historical volatility (based on a statistical analysis of the share price on a weighted moving average basis for the expected term of the option) | 44.40%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate |
Expected term (months) | 3 years |
Weighted average risk free interest rate | 2.20%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate |
Performance Shares |  |
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items] |  |
Weighted average historical volatility (based on a statistical analysis of the share price on a weighted moving average basis for the expected term of the option) |  | 33.10%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember
Expected term (months) |  | 3 years
Dividend yield |  | 4.60%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember
Weighted average fair value (South African rand) |  | 79.83 gfi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember
Performance Shares | US Interest Rates | 3 Year [Member] |  |
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items] |  |
Weighted average risk free interest rate |  | 0.20%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate / us-gaap_AwardTypeAxis = us-gaap_PerformanceSharesMember / us-gaap_RangeAxis = gfi_ThreeYearsMember / us-gaap_StatementScenarioAxis = gfi_UsInterestRatesMember
Bonus Shares |  |
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items] |  |
Weighted average historical volatility (based on a statistical analysis of the share price on a weighted moving average basis for the expected term of the option) | 43.50%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate / us-gaap_AwardTypeAxis = gfi_BonusShareMember | 32.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate / us-gaap_AwardTypeAxis = gfi_BonusShareMember
Dividend yield | 0.60%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate / us-gaap_AwardTypeAxis = gfi_BonusShareMember | 4.60%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate / us-gaap_AwardTypeAxis = gfi_BonusShareMember
Weighted average fair value (South African rand) | 40.28 gfi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue / us-gaap_AwardTypeAxis = gfi_BonusShareMember | 72.42 gfi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue / us-gaap_AwardTypeAxis = gfi_BonusShareMember
Bonus Shares | Minimum |  |
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items] |  |
Expected term (months) | 9 months | 9 months
Bonus Shares | Maximum |  |
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items] |  |
Expected term (months) | 18 months | 18 months
Bonus Shares | SA Interest Rates | 3 Year [Member] |  |
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items] |  |
Weighted average risk free interest rate | 5.50%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate / us-gaap_AwardTypeAxis = gfi_BonusShareMember / us-gaap_RangeAxis = gfi_ThreeYearsMember / us-gaap_StatementScenarioAxis = gfi_SaInterestRatesMember | 4.10%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate / us-gaap_AwardTypeAxis = gfi_BonusShareMember / us-gaap_RangeAxis = gfi_ThreeYearsMember / us-gaap_StatementScenarioAxis = gfi_SaInterestRatesMember

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- Definition The weighted average fair value of the share-based compensation awards/options. + References No definition available. + Details
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- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.D.2) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section D -Subsection 2 + Details
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iv) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Weighted average expected volatility rate of share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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