Property and Equipment (Narratives) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Net book value	$ 69.4	$ 73.7
Depreciation	38.0	40.1	$ 36.5
Cost of Sales [Member]
Property, Plant and Equipment [Line Items]
Depreciation	4.6	10.3	$ 7.7
Software Development
Property, Plant and Equipment [Line Items]
Net book value	34.2	34.8
Software Development Work-in-Progress
Property, Plant and Equipment [Line Items]
Net book value	$ 4.8	$ 6.4