Retirement Plans and Other Postretirement Benefits - Fair Value of Plan Assets (Details) - Defined Benefit Plan - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure
Plan assets amount	$ 19.8	$ 22.0	$ 23.2	$ 22.1
Equity security funds, United States
Defined Benefit Plan Disclosure
Plan assets amount	3.8	4.4
Equity security funds, International
Defined Benefit Plan Disclosure
Plan assets amount	3.3	4.3
Fixed income funds
Defined Benefit Plan Disclosure
Plan assets amount	12.4	13.1
Short-term investment funds
Defined Benefit Plan Disclosure
Plan assets amount	0.3	0.2
Level 1
Defined Benefit Plan Disclosure
Plan assets amount	0.3	0.2
Level 1 | Equity security funds, United States
Defined Benefit Plan Disclosure
Plan assets amount	0.0	0.0
Level 1 | Equity security funds, International
Defined Benefit Plan Disclosure
Plan assets amount	0.0	0.0
Level 1 | Fixed income funds
Defined Benefit Plan Disclosure
Plan assets amount	0.0	0.0
Level 1 | Short-term investment funds
Defined Benefit Plan Disclosure
Plan assets amount	0.3	0.2
Level 2
Defined Benefit Plan Disclosure
Plan assets amount	19.5	21.7
Level 2 | Equity security funds, United States
Defined Benefit Plan Disclosure
Plan assets amount	3.8	4.3
Level 2 | Equity security funds, International
Defined Benefit Plan Disclosure
Plan assets amount	3.3	4.3
Level 2 | Fixed income funds
Defined Benefit Plan Disclosure
Plan assets amount	12.4	13.1
Level 2 | Short-term investment funds
Defined Benefit Plan Disclosure
Plan assets amount	0.0	0.0
Level 3
Defined Benefit Plan Disclosure
Plan assets amount	0.0	0.0
Level 3 | Equity security funds, United States
Defined Benefit Plan Disclosure
Plan assets amount	0.0	0.0
Level 3 | Equity security funds, International
Defined Benefit Plan Disclosure
Plan assets amount	0.0	0.0
Level 3 | Fixed income funds
Defined Benefit Plan Disclosure
Plan assets amount	0.0	0.0
Level 3 | Short-term investment funds
Defined Benefit Plan Disclosure
Plan assets amount	$ 0.0	$ 0.0