BENEFIT PLANS: (Tables)

12 Months Ended

Dec. 31, 2024

Defined contribution plan and post-retirement defined benefit plans

Components of net periodic benefit costs

Schedule of the components of net periodic benefit costs

(in millions)	2024		2023		2022
Service cost	$	2.2	$	2.3	$	1.8
Interest cost		3.3		3.6		2.3
Expected return on plan assets		(5.5)		(5.9)		(3.9)
Amortization of net actuarial loss		—		0.1		0.1
Amortization of prior service cost / (credit)		0.2		0.7		0.2
Amortization of net loss/(gain)		0.3		0.3		0.3
Net periodic benefit cost	$	0.5	$	1.1	$	0.8

Schedule of changes in the benefit obligation and plan assets, the funded status of the plans and the amount recognized in balance sheet and accumulated other comprehensive income

	As of December 31,
(in millions)	2024		2023
Change in benefit obligation:
Projected benefit obligation at beginning of year	$	47.4	$	38.6
Service cost		2.2		2.3
Interest cost		3.3		3.6
Benefits paid		(4.4)		(3.9)
Actuarial loss		1.5		1.8
Actuarial loss (gain) assumption changes		(0.3)		0.6
Inflation adjustment		(6.7)		4.4
Projected benefit obligation at end of year	$	43.0	$	47.4
Change in plan assets:
Fair value of plan assets at beginning of year	$	73.2	$	59.2
Actual return on plan assets		16.1		8.8
Employer contributions		(0.6)		(1.0)
Benefits paid		(0.7)		(0.9)
Currency exchange rate adjustment		(10.6)		7.1
Fair value of plan assets at end of year	$	77.4	$	73.2
Funded status at end of year:	$	34.4	$	25.8
ASC-715 amounts recognized in statement of financial position consists of:
Non-current assets	$	34.4	$	25.8
Total	$	34.4	$	25.8
ASC-715 amounts recognized in accumulated other comprehensive income (net of income taxes of $(0.4) million and $(4.7) million in 2024 and 2023, respectively) consists of:
Net loss (gain)	$	(0.3)	$	6.2
Prior service cost		0.8		1.1
Total	$	0.5	$	7.3

Schedule of changes in accumulated other comprehensive income

(in millions)	2024		2023
Reconciliation of accumulated other comprehensive income:
Accumulated other comprehensive income at beginning of plan year	$	7.3	$	7.8
Net (gain) loss ocurring during the year		(5.8)		(0.6)
Net (gain) amortized during the year		(0.3)		(0.4)
Prior service cost (credit)		—		0.3
Settlement		(0.1)		(0.4)
Currency exchange rate adjustment		(0.6)		0.6
Net adjustment to accumulated other comprehensive income (net of income taxes of $4.3 million and $0.1 million in 2024 and 2023, respectively)		(6.8)		(0.5)
Accumulated other comprehensive income at end of plan year	$	0.5	$	7.3

Summary of the amounts in accumulated other comprehensive income amortized and recognized as a component of net periodic benefit cost, net of tax

(in millions)	2024		2023
Net loss / (gain)	$	(5.8)	$	(0.6)
Amortization of net (loss) gain		(0.3)		(0.4)
Amortization of prior services cost (credit)		—		0.3
Total amortization expenses	$	(6.1)	$	(0.7)

Schedule of assumptions used to determine the pension obligations and other post-retirement benefits

Mexican Plan(*)	2024		2023		2022
Discount rate	10.19	%	9.98	%	10.09	%
Expected long-term rate of return on plan asset	10.19	%	9.98	%	10.09	%
Rate of increase in future compensation level	4.75	%	5.00	%	4.75	%

Expatriate Plan	2024		2023		2022
Discount rate	5.30	%	4.65	%	4.85	%
Expected long-term rate of return on plan asset	4.00	%	4.50	%	4.00	%
Rate of increase in future compensation level	N/A		N/A		N/A

(*)These rates are based on Mexican pesos as pension obligations are denominated in this currency.

Scheduled maturities of the benefits expected to be paid in each of the next five years, and thereafter

	Expected
Years	Benefit Payments
	(in millions)
2025	$	8.2
2026		3.4
2027		4.3
2028		4.3
2029		3.9
2030 to 2034		24.9
Total	$	49.0

Post-retirement health care plans

Components of net periodic benefit costs

Schedule of the components of net periodic benefit costs

(in millions)	2024		2023		2022
Interest cost	$	1.8	$	2.2	$	1.7
Amortization of net loss (gain)		—		—		0.1
Net periodic benefit cost	$	1.8	$	2.2	$	1.8

Schedule of changes in the benefit obligation and plan assets, the funded status of the plans and the amount recognized in balance sheet and accumulated other comprehensive income

	As of December 31,
(in millions)	2024		2023
Change in benefit obligation:
Projected benefit obligation at beginning of year	$	22.7	$	20.3
Interest cost		1.8		2.2
Benefits paid		(1.4)		(1.1)
Actuarial (gain)		1.8		(1.6)
Inflation adjustment		(3.7)		2.9
Projected benefit obligation at end of year	$	21.2	$	22.7
Funded status at end of year:	$	21.2	$	22.7
ASC-715 amounts recognized in statement of financial position consists of:
Current liabilities	$	—	$	—
Non-current liabilities		(21.2)		(22.7)
Total	$	(21.2)	$	(22.7)
ASC-715 amounts recognized in accumulated other comprehensive income consists of:
Net loss (gain)	$	2.0	$	0.9
Total (net of income taxes of $(0.8) million and $(0.4) million in 2024 and 2023, respectively)	$	2.0	$	0.9

Schedule of changes in accumulated other comprehensive income

	As of December 31,
(in millions)	2024		2023
Reconciliation of accumulated other comprehensive income:
Accumulated other comprehensive income at beginning of plan year	$	0.9	$	1.6
Net loss/(gain) occurring during the year		1.2		(0.8)
Net loss/(gain) amortized during the year		—		—
Currency exchange rate adjustment		(0.1)		0.2
Net adjustment to accumulated other comprehensive income (net of income taxes of $0.5 million and $(0.4) million in 2024 and 2023, respectively)		1.1		(0.7)
Accumulated other comprehensive income at end of plan year	$	2.0	$	0.9

Summary of the amounts in accumulated other comprehensive income amortized and recognized as a component of net periodic benefit cost, net of tax

	As of December 31,
(in millions)	2024		2023
Net loss / (gain)	$	1.2	$	(0.8)
Amortization of net (loss) gain		—		—
Total amortization expenses	$	1.2	$	(0.8)

Schedule of assumptions used to determine the pension obligations and other post-retirement benefits

	2024		2023		2022
Mexican health plan
Weighted average discount rate	10.19	%	9.98	%	10.09	%
Expatriate health plan
Discount rate	5.30	%	4.65	%	4.85	%

Scheduled maturities of the benefits expected to be paid in each of the next five years, and thereafter

	Expected
Year	Benefit Payments
	(in millions)
2025	$	1.7
2026		1.7
2027		1.8
2028		1.8
2029		1.9
2030 to 2034		10.2
Total	$	19.1

Mexican Health Plan | Defined contribution plan and post-retirement defined benefit plans

Components of net periodic benefit costs

Schedule of asset mix of the investment portfolio

	2024		2023
Asset category:
Treasury bills	75	%	73	%
Equity securities	25	%	27	%
	100	%	100	%

Mexican Health Plan | Post-retirement health care plans

Components of net periodic benefit costs

Schedule of effects of one percentage-point change in assumed other benefits cost trend rates

	One Percentage
	Point
(in millions)	Increase		Decrease
Effect on total service and interest cost components	$	2.3	$	1.9
Effect on the post-retirement benefit obligation	$	21.7	$	19.9