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Provision for Post-Retirement Health Care Costs - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
 6 Months Ended 12 Months Ended
Dec. 30, 2010
Dec. 31, 2010
Dec. 31, 2012
Dec. 31, 2011
Jun. 30, 2010
Gold Fields Group (excluding South Deep)
          
Defined Benefit Plan Disclosure [Line Items]          
Contributions to post-retirement health care scheme   $ 0.5 $ 0.1 $ 0.2 $ 0.2
Health care cost, assumptions, inflation rate per annum     7.50% 8.00%  
Health care cost, assumptions, discount rate per annum     8.00% 8.75%  
Amount a one percentage point increase in assumed health care cost trend rates would have increased the aggregate of service and interest cost 0.01   0.02 0.03 0.10
Amount a one percentage point increase in assumed health care cost trend rates would have increased the accumulated post-retirement health care benefit     0.2 0.2  
Amount a one percentage point decrease in assumed health care cost trend rates would have decreased the aggregate of service and interest cost   0.01 0.01 0.01 0.01
Amount a one percentage point decrease in assumed health care cost trend rates would have decrease the accumulated post-retirement health care benefit obligation     0.2 0.2  
South Deep Gold Mine
          
Defined Benefit Plan Disclosure [Line Items]          
Contributions to post-retirement health care scheme   $ 0.1    $ 0.1 $ 0.1