Postretirement Benefits (Assets Carried at Fair Value by Level) (Details) - Pension Plan - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Pension assets	$ 25.4	$ 26.7	$ 26.3
Level 1
Defined Benefit Plan Disclosure [Line Items]
Pension assets	2.8	3.2
Level 2
Defined Benefit Plan Disclosure [Line Items]
Pension assets	21.6	22.4
Level 3
Defined Benefit Plan Disclosure [Line Items]
Pension assets	1.0	1.1
Fixed income bonds
Defined Benefit Plan Disclosure [Line Items]
Pension assets	21.6	22.5
Fixed income bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.2
Fixed income bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Pension assets	21.6	22.3
Fixed income bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.0
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Pension assets	2.8	3.0
Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Pension assets	2.8	3.0
Mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.0
Mutual funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.0
Pooled separate accounts
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.1
Pooled separate accounts | Level 1
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.0
Pooled separate accounts | Level 2
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.1
Pooled separate accounts | Level 3
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.0
Guaranteed deposit account
Defined Benefit Plan Disclosure [Line Items]
Pension assets	1.0	1.1
Guaranteed deposit account | Level 1
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.0
Guaranteed deposit account | Level 2
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0.0	0.0
Guaranteed deposit account | Level 3
Defined Benefit Plan Disclosure [Line Items]
Pension assets	$ 1.0	$ 1.1