INCOME TAXES: (Tables)

12 Months Ended

Dec. 31, 2022

INCOME TAXES:

Components of the provision for income taxes

(in millions)	2022		2021		2020
U.S. federal and state:
Current	$	0.1	$	—	$	—
Deferred		—		—		—
Uncertain tax positions		—		—		—
		0.1		—		—
Foreign (Peru and Mexico):
Current		1,443.1		2,425.5		1,237.9
Deferred		118.6		(126.3)		(63.5)
Uncertain tax positions		34.3		—		—
		1,596.0		2,299.2		1,174.4
Total provision for income taxes	$	1,596.1	$	2,299.2	$	1,174.4

Schedule of source of income

(in millions)	2022		2021		2020
Earnings by location:
U.S.	$	0.5	$	(32.4)	$	(15.3)
Foreign
Peru		1,167.8		1,962.8		723.9
Mexico		3,079.5		3,766.4		2,037.2
		4,247.3		5,729.2		2,761.1
Earnings before taxes on income	$	4,247.8	$	5,696.8	$	2,745.8

Reconciliation of the statutory income tax rate to the effective tax rate

The reconciliation of the statutory income tax rate to the effective tax rate for the three years ended December 31, 2022, is as follows (in percentage points):

	2022		2021		2020
Expected tax at U.S. statutory rate	21.0	%	21.0	%	21.0	%
Foreign tax at other than statutory rate, net of foreign tax credit benefit (1)	14.7		13.8		13.7
Percentage depletion	(2.1)		(1.8)		(2.2)
Other permanent differences	(0.1)		(0.3)		0.1
Additional valuation allowance on U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred taxes	5.5		8.4		8.9
Increase (decrease) in unrecognized tax benefits for uncertain tax positions	1.5		(0.5)		(0.1)
Amounts (over) / under provided in prior years	(1.7)		—		(0.1)
Other	(1.2)		(0.2)		1.5
Effective income tax rate	37.6	%	40.4	%	42.8	%

(1) Foreign tax at other than statutory rates, net of foreign tax credit benefit, also includes the effects of permanent differences in Peru and Mexico, that are determined at the local statutory rate.

Schedule of deferred tax assets and liabilities

	At December 31,
(in millions)	2022		2021
Assets:
Inventories	$	28.5	$	78.0
Capitalized exploration expenses		12.4		12.5
U.S. foreign tax credit carryforward, net of Uncertain Tax Positions		1,653.5		1,479.2
U.S. tax effect of Peruvian deferred tax liability		112.5		75.0
U.S. tax effect of Peruvian Uncertain Tax Positions		45.1		—
Reserves		249.6		284.5
Property, plant and equipment		—		9.5
Deferred workers participation		15.9		11.1
Accrued salaries, wages and vacations		7.4		8.2
Sales price adjustment (PUI)		—		2.6
Social responsibility expenses		—		5.1
Deferred charges		28.6		31.6
Valuation allowance on U.S. deferred tax assets, foreign tax credits and U.S. tax effect of Peruvian deferreds		(2,053.7)		(1,820.0)
Accrued royalty and special mining tax		10.8		23.3
Other		21.9		5.5
Total deferred tax assets		132.5		206.1
	At December 31,
(in millions)	2022		2021
Liabilities:
Property, plant and equipment		(19.7)		—
Social responsibility expenses		(7.7)		—
Sales price adjustment (PUI)		(29.0)		—
Other		—		(8.2)
Total deferred tax liabilities		(56.4)		(8.2)
Total net deferred tax (liabilities) / assets	$	76.1	$	197.9

Summary of expiry of foreign tax credits

Year	Amount
2024		72.2
2025		146.7
2026		96.1
2027		—
2028		175.0
2029		219.9
2030		247.6
2031		582.2
2032		131.0
Total	$	1,670.7

Schedule of reconciliation of amount of unrecognized tax benefits

The total amount of unrecognized tax benefits in 2022, 2021 and 2020, was as follows (in millions):

	2022		2021		2020
Unrecognized tax benefits, opening balance	$	—	$	66.1	$	58.4
Gross decreases—tax positions in prior period		—		(10.9)		—
Gross increases—tax positions in prior period		130.9		—		—
Gross increases—current-period tax positions		—		—		7.7
Gross decreases—current-period tax positions		(10.7)		(1.1)		—
Decreases related to settlements with taxing authorities		(37.5)		(54.1)		—
		82.7		(66.1)		7.7
Unrecognized tax benefits, ending balance	$	82.7	$	—	$	66.1

Summary of tax years remaining open to examination and adjustment in major tax jurisdictions

Peru:	2017 and all subsequent years
U.S.:	2017 and all subsequent years
Mexico:	2017 and all subsequent years