XML 237 R148.htm IDEA: XBRL DOCUMENT v3.22.0.1
FINANCIAL INSTRUMENTS - Hedging Instruments and Hedged Forecast Transactions (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Disclosure of detailed information about financial instruments [line items]    
Accumulated cash flow hedge fair reserve (before tax) $ 54.7 $ 30.6
Hedging instruments 54.7 30.6
Hedged items premiums paid (54.7) (30.6)
Canadian dollar contracts | Cash flow hedges    
Disclosure of detailed information about financial instruments [line items]    
Accumulated cash flow hedge fair reserve (before tax) 23.4 32.7
Hedging instruments 23.4 32.7
Hedged items premiums paid (23.4) (32.7)
Oil contracts | Cash flow hedges    
Disclosure of detailed information about financial instruments [line items]    
Accumulated cash flow hedge fair reserve (before tax) 31.3 (2.1)
Hedging instruments 31.3 (2.1)
Hedged items premiums paid (31.3) 2.1
Gold price contracts | Cash flow hedges    
Disclosure of detailed information about financial instruments [line items]    
Accumulated cash flow hedge fair reserve (before tax) 0.0 0.0
Hedging instruments 0.0 0.0
Hedged items premiums paid $ 0.0 $ 0.0