Retirement Benefits - Schedule of Fair Value Pension Plan Assets (Details) - Pension Benefits - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 499.0	$ 543.1	$ 515.4
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.0	18.0
Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14.7	22.9
Common Pooled Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	87.6	98.5
U.S. Treasuries
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	41.3	42.4
State and Local Municipal Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.6	7.6
Sovereign Debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.7	6.7
Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	131.1	120.3
Fixed Income Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15.7	47.0
Common Pooled Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	186.8	176.7
Alternative Investment Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.5	0.8
Common Pooled Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.0	2.2
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	31.9	82.4
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.1	12.1
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14.7	22.9
Quoted Prices in Active Markets for Identical Assets (Level 1) | Common Pooled Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasuries
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | State and Local Municipal Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Sovereign Debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed Income Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15.7	47.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Common Pooled Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Alternative Investment Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Common Pooled Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.4	0.4
Quoted Prices in Active Markets for Similar Assets (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	466.6	459.9
Quoted Prices in Active Markets for Similar Assets (Level 2) | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.9	5.9
Quoted Prices in Active Markets for Similar Assets (Level 2) | Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Similar Assets (Level 2) | Common Pooled Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	87.6	98.5
Quoted Prices in Active Markets for Similar Assets (Level 2) | U.S. Treasuries
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	41.3	42.4
Quoted Prices in Active Markets for Similar Assets (Level 2) | State and Local Municipal Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.6	7.6
Quoted Prices in Active Markets for Similar Assets (Level 2) | Sovereign Debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.7	6.7
Quoted Prices in Active Markets for Similar Assets (Level 2) | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	131.1	120.3
Quoted Prices in Active Markets for Similar Assets (Level 2) | Fixed Income Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Similar Assets (Level 2) | Common Pooled Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	186.8	176.7
Quoted Prices in Active Markets for Similar Assets (Level 2) | Alternative Investment Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Similar Assets (Level 2) | Common Pooled Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.6	1.8
Unobservable inputs for which little or no market data exists (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Common Pooled Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | U.S. Treasuries
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | State and Local Municipal Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Sovereign Debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Fixed Income Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Common Pooled Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Alternative Investment Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable inputs for which little or no market data exists (Level 3) | Common Pooled Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.5	0.8
Investments Priced Using Net Asset Value | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | Common Pooled Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | U.S. Treasuries
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | State and Local Municipal Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | Sovereign Debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | Fixed Income Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | Common Pooled Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Investments Priced Using Net Asset Value | Alternative Investment Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.5	0.8
Investments Priced Using Net Asset Value | Common Pooled Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0.0	$ 0.0