Benefit Plans - Fair Values of Pension Plan Assets by Asset Category (Details) - USD ($) $ in Millions | 12 Months Ended |
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | $ 460 | $ 682.4 | |
Total contribution to defined contribution plans | 46.6 | 40.6 | $ 35.9 |
Cash and cash equivalents | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 3.2 | 12.7 | |
Equity funds | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 90.7 | 181.8 | |
U.S. small-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 3.8 | 6.3 | |
U.S. large-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 22.4 | 37 | |
International equity | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 64.5 | 138.5 | |
Fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 322.7 | 403.4 | |
Corporate bonds - international | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 52.2 | 34.9 | |
UK index-linked gilts | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 41.6 | 35.9 | |
U.S. fixed income - government securities | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 33.1 | 38 | |
U.S. fixed income - short duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 1.8 | 5.2 | |
U.S. fixed income - intermediate duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 50.3 | 41.1 | |
U.S. fixed income - long corporate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 135.7 | 234.8 | |
Global fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 8 | 13.5 | |
International real estate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 16.6 | 49.5 | |
Other | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 26.8 | 35 | |
Investments Measured at NAV | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 286.3 | 446.8 | |
Investments Measured at NAV | Cash and cash equivalents | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Investments Measured at NAV | Equity funds | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 49.8 | 103.6 | |
Investments Measured at NAV | U.S. small-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 3.8 | 6.3 | |
Investments Measured at NAV | U.S. large-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 18.5 | 29 | |
Investments Measured at NAV | International equity | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 27.5 | 68.3 | |
Investments Measured at NAV | Fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 236.5 | 342.2 | |
Investments Measured at NAV | Corporate bonds - international | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 7.6 | 9.6 | |
Investments Measured at NAV | UK index-linked gilts | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Investments Measured at NAV | U.S. fixed income - government securities | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 33.1 | 38 | |
Investments Measured at NAV | U.S. fixed income - short duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 1.8 | 5.2 | |
Investments Measured at NAV | U.S. fixed income - intermediate duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 50.3 | 41.1 | |
Investments Measured at NAV | U.S. fixed income - long corporate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 135.7 | 234.8 | |
Investments Measured at NAV | Global fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 8 | 13.5 | |
Investments Measured at NAV | International real estate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Investments Measured at NAV | Other | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 1 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 23.3 | 37 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and cash equivalents | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 3.2 | 12.7 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity funds | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 20.1 | 24.3 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. small-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. large-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | International equity | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 20.1 | 24.3 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate bonds - international | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | UK index-linked gilts | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. fixed income - government securities | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. fixed income - short duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. fixed income - intermediate duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. fixed income - long corporate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Global fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | International real estate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | | | |
Significant Observable Inputs (Level 2) | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 123.6 | 164.6 | |
Significant Observable Inputs (Level 2) | Cash and cash equivalents | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Observable Inputs (Level 2) | Equity funds | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 20.8 | 53.9 | |
Significant Observable Inputs (Level 2) | U.S. small-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Observable Inputs (Level 2) | U.S. large-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 3.9 | 8 | |
Significant Observable Inputs (Level 2) | International equity | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 16.9 | 45.9 | |
Significant Observable Inputs (Level 2) | Fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 86.2 | 61.2 | |
Significant Observable Inputs (Level 2) | Corporate bonds - international | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 44.6 | 25.3 | |
Significant Observable Inputs (Level 2) | UK index-linked gilts | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 41.6 | 35.9 | |
Significant Observable Inputs (Level 2) | U.S. fixed income - government securities | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Observable Inputs (Level 2) | U.S. fixed income - short duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Observable Inputs (Level 2) | U.S. fixed income - intermediate duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Observable Inputs (Level 2) | U.S. fixed income - long corporate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Observable Inputs (Level 2) | Global fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Observable Inputs (Level 2) | International real estate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 16.6 | 49.5 | |
Significant Observable Inputs (Level 2) | Other | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 26.8 | 34 | |
Significant Unobservable Inputs (Level 3) | Cash and cash equivalents | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | Equity funds | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | U.S. small-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | U.S. large-cap | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | International equity | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | Fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | Corporate bonds - international | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | UK index-linked gilts | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | U.S. fixed income - government securities | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | U.S. fixed income - short duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | U.S. fixed income - intermediate duration | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | U.S. fixed income - long corporate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | Global fixed income | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | International real estate | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | 0 | 0 | |
Significant Unobservable Inputs (Level 3) | Other | | | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] | | | |
Fair value of plan assets | $ 26.8 | $ 34 | |