Restructuring Expenses and Asset Impairments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restructuring Cost and Reserve [Line Items]
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]			Restructuring expenses and asset impairments
Total restructuring costs		$ 10.9	$ 22.8	$ 9.3
Asset Impairments
Restructuring Cost and Reserve [Line Items]
Total restructuring costs		0.8	17.4	0.8
Corporate/Other
Restructuring Cost and Reserve [Line Items]
Total restructuring costs		0.5	0.3	2.6
Corporate/Other | Asset Impairments
Restructuring Cost and Reserve [Line Items]
Total restructuring costs		0.0	0.0	0.0
HST | Operating Segments
Restructuring Cost and Reserve [Line Items]
Contract with customer, amount reimbursed	$ 28.7
Impairment of definite-lived assets		16.8	16.8
Revenue recognized		17.9	17.9
Total restructuring costs		6.6	18.0	1.7
HST | Operating Segments | Asset Impairments
Restructuring Cost and Reserve [Line Items]
Total restructuring costs		0.0	16.8	0.0
FMT | Operating Segments
Restructuring Cost and Reserve [Line Items]
Total restructuring costs		2.9	2.7	4.5
FMT | Operating Segments | Asset Impairments
Restructuring Cost and Reserve [Line Items]
Total restructuring costs		$ 0.8	$ 0.5	$ 0.8