Employee Retirement Plans and Postretirement Benefits - Pension Fair Value Hierarchy (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	$ 2,834.5	$ 2,727.4	$ 3,396.9
Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	2,834.5	2,727.4	3,396.9
Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	776.0	923.9
Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	(408.4)	(201.5)
Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	768.3	733.8
Significant unobservable inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	416.1	391.6	$ 474.6
Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	416.1	391.6
Cash | Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	32.5	42.6
Cash | Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	32.5	42.6
Cash | Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Cash | Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Bank deposits, short-term bills and notes | Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	38.1	40.5
Bank deposits, short-term bills and notes | Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Bank deposits, short-term bills and notes | Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	38.1	40.5
Bank deposits, short-term bills and notes | Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Government debt securities | Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	297.9	290.6
Government debt securities | Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Government debt securities | Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	297.9	290.6
Government debt securities | Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Interest and inflation linked assets | Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	442.2	415.0
Interest and inflation linked assets | Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Interest and inflation linked assets | Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	432.3	402.7
Interest and inflation linked assets | Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	9.9	12.3
Annuities and longevity swap | Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	399.9	373.6
Annuities and longevity swap | Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Annuities and longevity swap | Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Annuities and longevity swap | Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	399.9	373.6
Repurchase agreements | Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	(441.5)	(244.2)
Repurchase agreements | Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	(441.5)	(244.2)
Repurchase agreements | Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Repurchase agreements | Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Recoverable taxes | Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.6	0.1
Recoverable taxes | Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.6	0.1
Recoverable taxes | Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Recoverable taxes | Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Debt funds | Fair Value Measured at Net Asset Value Per Share | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	1,297.3	1,266.2
Equity funds | Fair Value Measured at Net Asset Value Per Share | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	377.4	175.7
Real estate funds | Fair Value Measured at Net Asset Value Per Share | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	82.8	82.3
Private equity | Fair Value, Inputs, Level 1, 2 and 3 | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	6.3	5.7
Private equity | Quoted prices in active markets (Level 1) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Private equity | Significant observable inputs (Level 2) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	0.0	0.0
Private equity | Significant unobservable inputs (Level 3) | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	6.3	5.7
Private equity | Fair Value Measured at Net Asset Value Per Share | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	14.5	28.8
Hedge funds | Fair Value Measured at Net Asset Value Per Share | Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	$ 286.5	$ 250.5