Segment Information - Revenue, Properties and Outsourcing Assets by Geographic Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 446.7	$ 509.8
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	199.0	234.5
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	52.9	68.0
Other foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 194.8	$ 207.3