Defined contribution and defined benefit retirement plans (Tables)

12 Months Ended

Dec. 31, 2024

Defined benefit pension plans [Line Items]

Schedule of Composition of Pension Plan Assets

The composition of our pension plan assets by asset category and fair value level at December 31, 2023 and 2024 is shown in the tables below.

	Fair Value Measurements at December 31, 2023
			Quoted		Significant
			Prices in		Other		Significant
			Active		Observable		Unobservable		Assets
			Markets		Inputs		Inputs		measured
	Total		(Level 1)		(Level 2)		(Level 3)		at NAV
	(In millions)
Germany	$	269.4	$	—	$	—	$	269.4	$	—
Canada:
Non local currency equities		2.7		2.7		—		—		—
Local currency fixed income		86.2		86.2		—		—		—
Cash and other		1.1		1.1		—		—		—
Norway:
Local currency equities		2.4		2.4		—		—		—
Non local currency equities		7.2		7.2		—		—		—
Local currency fixed income		23.9		4.4		19.5		—		—
Non local currency fixed income		4.2		4.2		—		—		—
Real estate		6.6		—		—		6.6		—
Cash and other		3.0		2.8		—		.2		—
U.S.:
Equities		11.3		—		—		—		11.3
Fixed income		27.1		—		—		—		27.1
Cash and other		1.9		.7		—		—		1.2
Other		15.9		—		—		15.9		—
Total	$	462.9	$	111.7	$	19.5	$	292.1	$	39.6

	Fair Value Measurements at December 31, 2024
			Quoted		Significant
			Prices in		Other		Significant
			Active		Observable		Unobservable		Assets
			Markets		Inputs		Inputs		measured
	Total		(Level 1)		(Level 2)		(Level 3)		at NAV
	(In millions)
Germany	$	264.6	$	—	$	—	$	264.6	$	—
Canada:
Local currency equities		2.8		2.8		—		—		—
Local currency fixed income		78.1		78.1		—		—		—
Cash and other		.5		.5		—		—		—
Norway:
Local currency equities		2.0		2.0		—		—		—
Non local currency equities		6.9		6.9		—		—		—
Local currency fixed income		21.1		3.7		17.4		—		—
Non local currency fixed income		4.2		4.2		—		—		—
Real estate		6.2		—		—		6.2		—
Cash and other		3.6		3.4		—		.2		—
U.S.:
Equities		6.7		—		—		.1		6.6
Fixed income		30.8		—		—		—		30.8
Cash and other		38.2		37.0		—		—		1.2
Other		14.9		—		—		14.9		—
Total	$	480.6	$	138.6	$	17.4	$	286.0	$	38.6

A rollforward of the change in fair value of Level 3 assets follows.

	Years ended December 31,
	2023		2024
	(In millions)
Fair value at beginning of year	$	264.8	$	292.1
Gain on assets held at end of year		11.1		12.8
Gain (loss) on assets sold during the year		14.4		(.7)
Assets purchased		1.7		1.5
Assets sold		(9.3)		(2.3)
Currency exchange rate fluctuations		9.4		(17.4)
Fair value at end of year	$	292.1	$	286.0

Defined Benefit Pension Plans

Defined benefit pension plans [Line Items]

Schedule of Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)

The table below details the changes in other comprehensive income (loss) during 2022, 2023 and 2024.

		Years ended December 31,
		2022		2023		2024
	(In millions)
Changes in plan assets and benefit obligations recognized in   other comprehensive income (loss):
Net actuarial gains (losses)		$	134.1	$	(25.5)	$	16.0
Amortization of unrecognized:
Net actuarial losses			14.7		3.8		3.7
Prior service cost			.1		—		.1
Settlements			.4		6.5		.4
Total		$	149.3	$	(15.2)	$	20.2

Schedule of Rollforward of Change in Fair Value of Level 3 Assets

	Fair Value Measurements at December 31, 2024
			Quoted		Significant
			Prices in		Other		Significant
			Active		Observable		Unobservable		Assets
			Markets		Inputs		Inputs		measured
	Total		(Level 1)		(Level 2)		(Level 3)		at NAV
	(In millions)
Germany	$	264.6	$	—	$	—	$	264.6	$	—
Canada:
Local currency equities		2.8		2.8		—		—		—
Local currency fixed income		78.1		78.1		—		—		—
Cash and other		.5		.5		—		—		—
Norway:
Local currency equities		2.0		2.0		—		—		—
Non local currency equities		6.9		6.9		—		—		—
Local currency fixed income		21.1		3.7		17.4		—		—
Non local currency fixed income		4.2		4.2		—		—		—
Real estate		6.2		—		—		6.2		—
Cash and other		3.6		3.4		—		.2		—
U.S.:
Equities		6.7		—		—		.1		6.6
Fixed income		30.8		—		—		—		30.8
Cash and other		38.2		37.0		—		—		1.2
Other		14.9		—		—		14.9		—
Total	$	480.6	$	138.6	$	17.4	$	286.0	$	38.6

A rollforward of the change in fair value of Level 3 assets follows.

	Years ended December 31,
	2023		2024
	(In millions)
Fair value at beginning of year	$	264.8	$	292.1
Gain on assets held at end of year		11.1		12.8
Gain (loss) on assets sold during the year		14.4		(.7)
Assets purchased		1.7		1.5
Assets sold		(9.3)		(2.3)
Currency exchange rate fluctuations		9.4		(17.4)
Fair value at end of year	$	292.1	$	286.0

Defined Benefit Pension Plans | United States

Defined benefit pension plans [Line Items]

Schedule of Defined Benefit Plan Expected Future Payments

Years ending December 31,	Amount
	(In millions)
2025	$	29.9
2026		30.5
2027		32.5
2028		37.4
2029		36.0
Next 5 years		175.9

Schedule of Funded Status

The funded status of our U.S. defined benefit pension plans, including the acquired LPC plan, is presented in the table below.

	Years ended December 31,
	2023		2024
	(In millions)
Change in projected benefit obligations ("PBO"):
Balance at beginning of the year	$	43.4	$	42.7
Interest cost		2.2		2.7
Actuarial (gains) losses		1.2		(3.1)
Benefits paid		(4.1)		(4.6)
Acquisition		—		27.5
Balance at end of the year	$	42.7	$	65.2
Change in plan assets:
Fair value at beginning of the year	$	39.1	$	40.3
Actual return on plan assets		3.7		.4
Employer contributions		1.6		1.5
Benefits paid		(4.1)		(4.6)
Acquisition		—		38.1
Fair value at end of the year	$	40.3	$	75.7
Funded status	$	(2.4)	$	10.5
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	$	—	$	10.7
Accrued pension costs:
Current		—		(.1)
Noncurrent		(2.4)		(.1)
Total		(2.4)		10.5
Accumulated other comprehensive loss - actuarial losses		30.3		28.5
Total	$	27.9	$	39.0
Accumulated benefit obligations ("ABO")	$	42.7	$	65.2

Schedule of Components of Net Periodic Defined Benefit Cost

The components of our net periodic defined benefit pension cost for U.S. plans are presented in the table below. The amounts shown below for the amortization of recognized actuarial losses for 2022, 2023 and 2024 were recognized as components of our accumulated other comprehensive income (loss) at December 31, 2021, 2022 and 2023, respectively, net of deferred income taxes and noncontrolling interest.

	Years ended December 31,
	2022		2023		2024
	(In millions)
Net periodic pension cost for U.S. plans:
Interest cost	$	1.4	$	2.2	$	2.7
Expected return on plan assets		(2.0)		(1.9)		(3.2)
Recognized net actuarial losses		1.9		2.0		1.9
Total	$	1.3	$	2.3	$	1.4

Schedule of Plans for which Accumulated Benefit Obligations Exceeds Plan Assets

Information concerning our U.S. defined benefit pension plans (for which the ABO of all of the plans exceeds the fair value of plan assets as of the indicated date) is presented in the table below.

	December 31,
	2023		2024
	(In millions)
Plans for which the ABO exceeds plan assets:
Projected benefit obligations	$	42.7	$	.1
Accumulated benefit obligations		42.7		.1
Fair value of plan assets		40.3		—

Summary of Actuarial Assumptions Used to Determine the Benefit Obligation and Net Benefit Cost

The weighted-average rate assumptions used in determining the net periodic pension cost for our U.S. defined benefit pension plans for 2022, 2023 and 2024 are presented in the table below. The impact of assumed increases in future compensation levels does not have an effect on the periodic pension cost as the plans are frozen with regards to compensation.

	Years ended December 31,
	2022	2023	2024
Discount rate	2.6%	5.3%	5.0%
Long-term return on plan assets	4.0%	5.0%	5.0%

Defined Benefit Pension Plans | Non U.S.

Defined benefit pension plans [Line Items]

Schedule of Funded Status

The funded status of our non-U.S. defined benefit pension plans is presented in the table below.

	Years ended December 31,
	2023		2024
	(In millions)
Change in PBO:
Balance at beginning of the year	$	508.6	$	563.7
Service cost		6.3		6.6
Interest cost		19.8		18.9
Participants’ contributions		1.8		1.8
Actuarial (gains) losses		44.3		(16.2)
Settlements		(8.6)		(1.9)
Change in currency exchange rates		14.1		(36.8)
Benefits paid		(22.6)		(22.8)
Balance at end of the year	$	563.7	$	513.3
Change in plan assets:
Fair value at beginning of the year	$	390.5	$	422.6
Actual return on plan assets		37.4		20.0
Employer contributions		14.7		14.9
Participants' contributions		1.8		1.8
Settlements		(8.6)		(1.9)
Change in currency exchange rates		9.4		(29.7)
Benefits paid		(22.6)		(22.8)
Fair value at end of the year	$	422.6	$	404.9
Funded status	$	(141.1)	$	(108.4)
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	$	8.1	$	9.1
Noncurrent accrued pension costs		(149.2)		(117.5)
Total		(141.1)		(108.4)
Accumulated other comprehensive loss:
Actuarial losses		106.8		88.8
Prior service cost		.3		.3
Total		107.1		89.1
Total	$	(34.0)	$	(19.3)
ABO	$	549.8	$	499.7

Schedule of Components of Net Periodic Defined Benefit Cost

The components of our net periodic pension benefit cost for our non-U.S. plans are presented in the table below.

	Years ended December 31,
	2022		2023		2024
	(In millions)
Net periodic pension cost for non-U.S. plans:
Service cost	$	11.3	$	6.3	$	6.6
Interest cost		10.6		19.8		18.9
Expected return on plan assets		(11.1)		(18.3)		(19.9)
Recognized net actuarial losses		12.8		1.8		1.9
Amortization of prior service cost		.1		—		.1
Settlements		.4		6.5		.4
Total	$	24.1	$	16.1	$	8.0

Schedule of Plans for which Accumulated Benefit Obligations Exceeds Plan Assets

Information concerning certain of our non-U.S. defined benefit pension plans (for which the ABO exceeds the fair value of plan assets as of the indicated date) is presented in the table below.

	December 31,
	2023		2024
	(In millions)
Plans for which the ABO exceeds plan assets:
Projected benefit obligations	$	463.1	$	397.1
Accumulated benefit obligations		452.9		387.1
Fair value of plan assets		313.8		279.5

Summary of Actuarial Assumptions Used to Determine the Benefit Obligation and Net Benefit Cost

The key actuarial assumptions used to determine our non-U.S. benefit obligations as of December 31, 2023 and 2024 are as follows:

	December 31,
	2023	2024
Discount rate	3.4%	3.6%
Increase in future compensation levels	2.7%	2.8%

A summary of our key actuarial assumptions used to determine non-U.S. net periodic benefit cost for 2022, 2023 and 2024 are as follows:

	Years ended December 31,
	2022	2023	2024
Discount rate	1.5%	3.9%	3.4%
Increase in future compensation levels	2.6%	2.7%	2.7%
Long-term return on plan assets	2.5%	4.6%	4.9%