Segment Information - Revenue, Properties and Outsourcing Assets by Geographic Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 516.4	$ 446.7
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	201.0	199.0
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	121.9	52.9
Other foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 193.5	$ 194.8