Segment and Geographical Area Information (External Revenue and Long-Lived Assets) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	$ 672.1	$ 617.4	$ 1,980.1	$ 1,804.4
Long-lived assets	244.7		244.7		$ 231.9
United States
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	485.2	440.7	1,426.3	1,296.8
Long-lived assets	182.7		182.7		178.6
Total International
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	186.9	176.7	553.8	507.6
Long-lived assets	62.0		62.0		53.3
Canada
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	47.6	48.2	144.1	140.1
Long-lived assets	5.2		5.2		4.9
Continental Europe
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	58.6	55.1	170.6	160.7
Long-lived assets	5.0		5.0		6.3
Australia
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	19.3	16.7	56.8	48.0
Long-lived assets	0.7		0.7		1.1
Canada
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	44.9	41.0	134.2	112.7
Long-lived assets	19.4		19.4		17.9
United Kingdom
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	12.8	12.4	36.7	36.5
Long-lived assets	31.5		31.5		22.8
Other
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items]
External revenue	3.7	$ 3.3	11.4	$ 9.6
Long-lived assets	$ 0.2		$ 0.2		$ 0.3