Employee Benefits - Benefit Obligations and Funded Status of Pension Plans, OPEB and Salaried VEBAs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024		Dec. 31, 2023
Amounts recognized on our Consolidated Balance Sheets:
Pension and OPEB	$ (73.4)	$ (71.4)	[1]
Salaried VEBA
Change in benefit obligation:
Obligation at beginning of year	42.9	46.9
Interest cost	2.2	2.2
Prior service cost	0.0
Actuarial loss (gain)	(2.3)	(1.4)
Benefits paid	(4.7)	(4.8)
Obligation at end of year	38.1	42.9		$ 46.9
Change in plan assets:
Fair market value of plan assets at beginning of year	42.9	43.1
Actual return on assets	6.7	3.9
Company contributions	2.9	0.7
Benefits paid	(4.7)	(4.8)
Fair market value of plan assets at end of year	47.8	42.9		43.1
Net funded status	9.7
Amounts recognized on our Consolidated Balance Sheets:
Total	9.7
Cumulative gain (loss) recognized in AOCI:
Accumulated net actuarial gain	14.5	8.2
Prior service cost	(11.3)	(14.3)
Total	3.2	(6.1)
Salaried VEBA | Other Assets
Amounts recognized on our Consolidated Balance Sheets:
Other assets	9.7
Pension Plans
Change in benefit obligation:
Obligation at beginning of year	30.7	30.5
Foreign currency translation loss (gain)	0.2	(0.5)
Service cost	3.4	3.6		3.8
Interest cost	1.7	1.6		1.3
Prior service cost		2.2
Actuarial loss (gain)	0.6	(1.6)
Plan participants contributions	0.1	0.1
Benefits paid	(0.7)	(0.7)
Settlements	0.0	(4.5)
Obligation at end of year	36.0	30.7		30.5
Change in plan assets:
Fair market value of plan assets at beginning of year	22.5	20.5
Foreign currency translation gain	0.2	0.3
Actual return on assets	1.9	0.9
Plan participants contributions	0.1	0.1
Company contributions	6.2	5.9
Benefits paid	(0.7)	(0.7)
Settlements	0.0	(4.5)
Fair market value of plan assets at end of year	30.2	22.5		20.5
Net funded status	(5.8)	(8.2)
Amounts recognized on our Consolidated Balance Sheets:
Total	(5.8)	(8.2)
Cumulative gain (loss) recognized in AOCI:
Accumulated net actuarial gain	3.9	4.2
Prior service cost	(6.7)	(7.6)
Total	(2.8)	(3.4)
Pension Plans | Other Assets
Amounts recognized on our Consolidated Balance Sheets:
Other assets	1.3	1.6
Pension Plans | Pension and Other Postretirement Benefits
Amounts recognized on our Consolidated Balance Sheets:
Pension and OPEB	(7.1)	(9.8)
Other Postretirement Benefits Plan
Change in benefit obligation:
Obligation at beginning of year	64.7	68.8
Service cost	1.0	1.1		1.1
Interest cost	3.5	3.3		3.4
Actuarial loss (gain)	3.6	(6.8)
Plan participants contributions	0.2	0.2
Benefits paid	(3.0)	(1.9)
Obligation at end of year	70.0	64.7		$ 68.8
Change in plan assets:
Plan participants contributions	0.2	0.2
Company contributions	2.8	1.7
Benefits paid	(3.0)	(1.9)
Net funded status	(70.0)	(64.7)
Amounts recognized on our Consolidated Balance Sheets:
Total	(70.0)	(64.7)
Cumulative gain (loss) recognized in AOCI:
Accumulated net actuarial gain	17.6	23.1
Total	17.6	23.1
Other Postretirement Benefits Plan | Accrued Salaries and Wages and Related Expenses
Amounts recognized on our Consolidated Balance Sheets:
Accrued salaries, wages and related expenses	(3.7)	(3.1)
Other Postretirement Benefits Plan | Pension and Other Postretirement Benefits
Amounts recognized on our Consolidated Balance Sheets:
Pension and OPEB	$ (66.3)	$ (61.6)

[1] Adjusted to reflect the retrospective change in inventory valuation methodology from LIFO to WAC. See Note 18 for further discussion.