INCOME TAXES: (Details) € in Millions, $ in Millions	6 Months Ended			12 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2025 EUR (€)	Jun. 30, 2024 USD ($)	Dec. 31, 2024
INCOME TAXES
Statutory income tax provision	$ 930.0		$ 852.3
Peruvian royalty	33.3		29.1
Mexican royalty	94.7		75.7
Peruvian special mining tax	50.7		45.0
Total income tax provision	$ 1,108.7		$ 1,002.1
Effective income tax rate (as a percent)	36.70%	36.70%	37.30%
Threshold minimum aggregate revenue under pillar two tax rules | €		€ 750
Global minimum tax rate	15.00%	15.00%
Peru
INCOME TAXES
Royalty charges	$ 84.0		$ 74.1
Uncertain tax positions	35.4
Increase (decrease) in income tax expense (benefit)	13.9
Unrecognized tax benefits	21.8
Mexico
INCOME TAXES
Mexican royalty	$ 94.7		$ 75.7
Mining royalty tax (as a percent)	8.50%	8.50%		7.50%
Additional royalty tax (as a percent)	1.00%	1.00%		0.50%