Properties - Components of Properties (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total properties	$ 727.0	$ 784.0
Land
Property, Plant and Equipment [Line Items]
Total properties	2.3	2.3
Buildings
Property, Plant and Equipment [Line Items]
Total properties	63.5	63.5
Machinery and office equipment
Property, Plant and Equipment [Line Items]
Total properties	466.7	521.5
Internal-use software
Property, Plant and Equipment [Line Items]
Total properties	171.2	161.8
Rental equipment
Property, Plant and Equipment [Line Items]
Total properties	$ 23.3	$ 34.9