Pension And Other Benefit Plans - Fair Values Of Pension Plan Assets (Details) - Defined benefit pension plans - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	$ 80.6	$ 104.1	$ 105.4
Quoted Prices in Active Market (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	0.3	0.3
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	0.0	0.0
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	50.1	77.2	$ 80.7
Total
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	50.4	77.5
Cash and cash equivalents | Quoted Prices in Active Market (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	0.3	0.3
Cash and cash equivalents | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	0.0	0.0
Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	0.0	0.0
Cash and cash equivalents | Total
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	0.3	0.3
Insurance contracts | Quoted Prices in Active Market (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	0.0	0.0
Insurance contracts | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	0.0	0.0
Insurance contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	50.1	77.2
Insurance contracts | Total
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	50.1	77.2
Mutual funds | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets	$ 30.2	$ 26.6