Defined contribution and defined benefit retirement plans (Tables)

12 Months Ended

Dec. 31, 2025

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, 2024 and 2025 is shown in the tables below.

	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

	Fair Value Measurements at December 31, 2025
			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	$	304.9	$	—	$	—	$	304.9	$	—
Canada:
Local currency equities		2.5		2.5		—		—		—
Local currency fixed income		79.1		79.1		—		—		—
Cash and other		.1		.1		—		—		—
Norway:
Local currency equities		2.3		2.3		—		—		—
Non local currency equities		7.5		7.5		—		—		—
Local currency fixed income		25.7		4.7		21.0		—		—
Non local currency fixed income		4.8		4.8		—		—		—
Real estate		7.4		—		—		7.4		—
Cash and other		4.5		4.4		—		.1		—
U.S.:
Cash and other		9.0		8.0		—		—		1.0
Other		17.1		—		—		17.1		—
Total	$	464.9	$	113.4	$	21.0	$	329.5	$	1.0

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

	Years ended December 31,
	2024		2025
	(In millions)
Fair value at beginning of year	$	292.1	$	286.0
Gain on assets held at end of year		12.8		13.8
Gain (loss) on assets sold during the year		(.7)		(6.7)
Assets purchased		1.5		1.6
Assets sold		(2.3)		(2.0)
Currency exchange rate fluctuations		(17.4)		36.8
Fair value at end of year	$	286.0	$	329.5

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 2023, 2024 and 2025.

		Years ended December 31,
		2023		2024		2025
	(In millions)
Changes in plan assets and benefit obligations recognized in   other comprehensive income (loss):
Net actuarial gains (losses)		$	(25.5)	$	16.0	$	39.0
Amortization of unrecognized:
Net actuarial losses			3.8		3.7		3.1
Prior service cost			—		.1		.1
Settlement loss			6.5		.4		29.0
Total		$	(15.2)	$	20.2	$	71.2

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

	Fair Value Measurements at December 31, 2025
			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	$	304.9	$	—	$	—	$	304.9	$	—
Canada:
Local currency equities		2.5		2.5		—		—		—
Local currency fixed income		79.1		79.1		—		—		—
Cash and other		.1		.1		—		—		—
Norway:
Local currency equities		2.3		2.3		—		—		—
Non local currency equities		7.5		7.5		—		—		—
Local currency fixed income		25.7		4.7		21.0		—		—
Non local currency fixed income		4.8		4.8		—		—		—
Real estate		7.4		—		—		7.4		—
Cash and other		4.5		4.4		—		.1		—
U.S.:
Cash and other		9.0		8.0		—		—		1.0
Other		17.1		—		—		17.1		—
Total	$	464.9	$	113.4	$	21.0	$	329.5	$	1.0

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

	Years ended December 31,
	2024		2025
	(In millions)
Fair value at beginning of year	$	292.1	$	286.0
Gain on assets held at end of year		12.8		13.8
Gain (loss) on assets sold during the year		(.7)		(6.7)
Assets purchased		1.5		1.6
Assets sold		(2.3)		(2.0)
Currency exchange rate fluctuations		(17.4)		36.8
Fair value at end of year	$	286.0	$	329.5

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)
2026	$	26.2
2027		28.3
2028		32.2
2029		31.7
2030		31.6
Next 5 years		154.4

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,
	2024		2025
	(In millions)
Change in projected benefit obligations ("PBO"):
Balance at beginning of the year	$	42.7	$	65.2
Interest cost		2.7		3.4
Actuarial (gains) losses		(3.1)		2.4
Benefits paid		(4.6)		(5.3)
Acquisition		27.5		—
Settlement		—		(65.6)
Balance at end of the year	$	65.2	$	.1
Change in plan assets:
Fair value at beginning of the year	$	40.3	$	75.7
Actual return on plan assets		.4		3.3
Employer contributions		1.5		—
Benefits paid		(4.6)		(5.3)
Acquisition		38.1		—
Settlement		—		(64.7)
Fair value at end of the year	$	75.7	$	9.0
Funded status	$	10.5	$	8.9
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	$	10.7	$	9.0
Accrued pension costs:
Current		(.1)		(.1)
Noncurrent		(.1)		—
Total		10.5		8.9
Accumulated other comprehensive loss - actuarial losses		28.5		—
Total	$	39.0	$	8.9
Accumulated benefit obligations ("ABO")	$	65.2	$	.1

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 2023, 2024 and 2025 were recognized as components of our accumulated other comprehensive income (loss) at December 31, 2022, 2023 and 2024, respectively, net of deferred income taxes and noncontrolling interest.

	Years ended December 31,
	2023		2024		2025
	(In millions)
Net periodic pension cost for U.S. plans:
Interest cost	$	2.2	$	2.7	$	3.4
Expected return on plan assets		(1.9)		(3.2)		(3.6)
Recognized net actuarial losses		2.0		1.9		1.4
Settlements		—		—		28.7
Total	$	2.3	$	1.4	$	29.9

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,
	2024		2025
	(In millions)
Plans for which the ABO exceeds plan assets:
Projected benefit obligations	$	.1	$	.1
Accumulated benefit obligations		.1		.1

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 2023, 2024 and 2025 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,
	2023	2024	2025
Discount rate	5.3%	5.0%	5.5%
Long-term return on plan assets	5.0%	5.0%	5.0%

Defined Benefit Pension Plans | Foreign Plan [Member]

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,
	2024		2025
	(In millions)
Change in PBO:
Balance at beginning of the year	$	563.7	$	513.3
Service cost		6.6		6.0
Interest cost		18.9		19.9
Participant contributions		1.8		2.0
Actuarial gains		(16.2)		(47.7)
Settlements		(1.9)		(1.4)
Change in currency exchange rates		(36.8)		57.8
Benefits paid		(22.8)		(24.5)
Balance at end of the year	$	513.3	$	525.4
Change in plan assets:
Fair value at beginning of the year	$	422.6	$	404.9
Actual return on plan assets		20.0		13.9
Employer contributions		14.9		15.9
Participant contributions		1.8		2.0
Settlements		(1.9)		(1.4)
Change in currency exchange rates		(29.7)		45.1
Benefits paid		(22.8)		(24.5)
Fair value at end of the year	$	404.9	$	455.9
Funded status	$	(108.4)	$	(69.5)
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	$	9.1	$	11.4
Noncurrent accrued pension costs		(117.5)		(80.9)
Total		(108.4)		(69.5)
Accumulated other comprehensive loss:
Actuarial losses		88.8		44.9
Prior service cost		.3		.3
Total	$	89.1	$	45.2
ABO	$	499.7	$	514.1

Schedule of Components of Net Periodic Defined Benefit Cost

Years ended December 31, 

	Years ended December 31,
	2023		2024		2025
	(In millions)
Net periodic pension cost for non-U.S. plans:
Service cost	$	6.3	$	6.6	$	6.0
Interest cost		19.8		18.9		19.9
Expected return on plan assets		(18.3)		(19.9)		(19.2)
Recognized net actuarial losses		1.8		1.9		1.7
Amortization of prior service cost		—		.1		.1
Settlements		6.5		.4		.3
Total	$	16.1	$	8.0	$	8.8

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,
	2024		2025
	(In millions)
Plans for which the ABO exceeds plan assets:
Projected benefit obligations	$	397.1	$	429.4
Accumulated benefit obligations		387.1		421.5
Fair value of plan assets		279.5		348.2

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, 2024 and 2025 are as follows:

	December 31,
	2024	2025
Discount rate	3.6%	4.3%
Increase in future compensation levels	2.8%	2.8%

A summary of our key actuarial assumptions used to determine non-U.S. net periodic benefit cost for 2023, 2024 and 2025 are as follows:

	Years ended December 31,
	2023	2024	2025
Discount rate	3.9%	3.4%	3.6%
Increase in future compensation levels	2.7%	2.7%	2.8%
Long-term return on plan assets	4.6%	4.9%	4.5%