Employee Benefit Plans - Fair Value Measurements (Details) - Quoted Prices in Active Markets for Identical Assets (Level 1) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plans
Fair value of plan assets	$ 149.2	$ 162.4
Cash
Defined Benefit Plans
Fair value of plan assets	0.6	0.6
U.S. treasury bonds
Defined Benefit Plans
Fair value of plan assets	$ 22.7	21.0
Equity mutual funds
Defined Benefit Plans
Target allocation percentage of investments	12.00%
Fair value of plan assets	$ 15.2	19.0
Fixed income mutual funds
Defined Benefit Plans
Target allocation percentage of investments	88.00%
Fair value of plan assets	$ 110.7	$ 121.8