Retirement Plans, Postretirement and Postemployment Benefits - Schedule of Fair Values of Pension Plan Assets by Asset Class and Fair Value Hierarchy Level (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	$ 1,067.1	$ 1,200.3
Quoted Prices In Active Markets For Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	0.2	3.9
Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	1,066.9	1,196.4
Mid-sized to Large Cap
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	291.6	351.6
Mid-sized to Large Cap | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	291.6	351.6
Small Cap, International and Emerging Growth Funds
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	287.2	354.5
Small Cap, International and Emerging Growth Funds | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	287.2	354.5
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	249.1	319.3
Debt Securities | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	249.1	319.3
Real Estate
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	151.5	86.6
Real Estate | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	151.5	86.6
Private infrastructure
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	83.1	78.5
Private infrastructure | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	83.1	78.5
Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets		5.9
Hedge Funds | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets		5.9
Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	4.6	3.9
Cash Equivalents | Quoted Prices In Active Markets For Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	0.2	$ 3.9
Cash Equivalents | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of pension plan assets	$ 4.4