Supplemental Financial Data - Property, Plant and Equipment - Net (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Less: accumulated depreciation	$ 27.5	$ 14.3
Property, plant and equipment - net	96.8	25.7	[1]
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7.7	0.0
Building and building improvement
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	61.8	0.0
Less: accumulated depreciation	0.7	0.0
Property, plant and equipment - net	61.1	0.0
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	38.2	24.4
Less: accumulated depreciation	19.5	9.5
Property, plant and equipment - net	18.7	14.9
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	16.6	15.6
Less: accumulated depreciation	7.3	4.8
Property, plant and equipment - net	$ 9.3	$ 10.8

[1] See discussion in Note 1 - Basis of Presentation and Description of Business for further detail regarding the elimination of the International lag reporting.