Average strike price.

No definition available.

Name:	gfi_AverageStrikePrice
Namespace Prefix:	gfi_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represents information about financial risk management.

+ References

No definition available.

+ Details

Name:	gfi_DisclosureOfFinancialRiskManagementLineItems
Namespace Prefix:	gfi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Unrealized Gain (loss) on hedge ineffectiveness

+ References

No definition available.

+ Details

Name:	gfi_UnrealizedGainlossOnHedgeIneffectiveness
Namespace Prefix:	gfi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The gains (losses) on the ineffective portion of hedges of net investments in foreign operations recognised in profit or loss. [Refer: Hedges of net investment in foreign operations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2021-01-01
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 24
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_24_c&doctype=Standard&book=b
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_GainsLossesOnIneffectivenessOfHedgesOfNetInvestmentsInForeignOperations
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of a hedging instrument, recognised as a liability. [Refer: Hedging instruments [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 24A
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_24A_a&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_HedgingInstrumentLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The nominal or face amount of a financial instrument, used to calculate payments made on that instrument.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_NotionalAmount
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of risk exposure associated with financial instruments with a shared characteristic that identifies a concentration of risks. [Refer: Financial instruments, class [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph B8
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_B8_c&doctype=Appendix&subtype=B
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_RiskExposureAssociatedWithInstrumentsSharingCharacteristic
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_CurrencyRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_AU
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=ifrs-full_ForwardContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfHedgesAxis=gfi_SalaresNortesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Risk Management Activities - Market Risk - Foreign Currency - Additional Information (Detail) $ in Millions, $ in Millions							12 Months Ended
	Mar. 31, 2020 USD ($)	Dec. 31, 2018 USD ($) $ / USD	Oct. 31, 2018 USD ($) $ / USD	Sep. 30, 2018 USD ($) $ / USD	Jun. 30, 2018 USD ($) $ / USD	May 31, 2018 USD ($) $ / USD	Dec. 31, 2020 USD ($)	Dec. 31, 2020 AUD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 AUD ($)	Dec. 31, 2020 AUD ($)	Dec. 31, 2019 AUD ($)
Disclosure of Financial Risk Management [line items]
Term loan and revolving credit facility							$ 1,200.0
Average strike rate	836.45
Currency risk [member]
Disclosure of Financial Risk Management [line items]
Exposure to risk relating to financial instruments							0.0
Currency risk [member] \| AUSTRALIA
Disclosure of Financial Risk Management [line items]
Average strike rate \| $ / USD		0.715	0.7075	0.7182	0.7330	0.7517
Currency risk [member] \| Forward contract [member] \| Salares Nortes [Member]
Disclosure of Financial Risk Management [line items]
Term loan and revolving credit facility	$ 544.5
Mark to Market value							86.0		$ 0.0
Gains (losses) on ineffectiveness of hedges of net investments in foreign operations recognised in profit or loss							5.2		0.0
Hedging instrument, liabilities							86.0		0.0
Unrealized Gain (loss) on hedge ineffectiveness							86.0		0.0
Currency risk [member] \| Forward contract [member] \| AUSTRALIA
Disclosure of Financial Risk Management [line items]
Term loan and revolving credit facility		$ 50.0	$ 60.0	$ 100.0	$ 60.0	$ 96.0
Mark to Market value							0.0		0.3		$ 0.0	$ 0.4
Gains (losses) on ineffectiveness of hedges of net investments in foreign operations recognised in profit or loss							0.3	$ 0.4	15.5	$ 22.3
Hedging instrument, liabilities							0.0		0.3		$ 0.0	$ 0.4
Unrealized Gain (loss) on hedge ineffectiveness							$ 0.0	$ 0.0	$ 8.3	$ 11.9