Benefit Plans - Amounts Recognized in Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Current liabilities	$ (2.4)	$ (2.3)
Noncurrent liabilities	(40.5)	(57.5)
Pension benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Noncurrent assets	16.7	12.9
Current liabilities	(1.7)	(1.6)
Noncurrent liabilities	(35.6)	(52.1)
Total liabilities	(20.6)	(40.8)
Other retirement benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Noncurrent assets	0.0	0.0
Current liabilities	(0.7)	(0.7)
Noncurrent liabilities	(4.9)	(5.4)
Total liabilities	$ (5.6)	$ (6.1)