Segment and Geographical Area Information (Operating Lease Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	$ 144.8	$ 0.0
United States [Member]
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	86.4	0.0
UNITED KINGDOM
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	17.9	0.0
Europe excluding the United Kingdom [Member]
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	6.3	0.0
AUSTRALIA
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	5.8	0.0
CANADA
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	7.5	0.0
Asia [Member]
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	20.2	0.0
Segment, Geographical, Group of Other Countries [Member]
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	0.7	0.0
Non United States [Member]
Segment Reporting Information [Line Items]
Operating Lease, Right-of-Use Asset	$ 58.4	$ 0.0