Leases (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Leases
Operating lease cost	$ 21.2	$ 17.6	$ 41.3	$ 35.2
Variable fees and other	7.2	8.3	15.2	15.9
Total lease cost	$ 28.4	$ 25.9	56.5	51.1
Cash payments for operating leases			55.8	51.3
Right-of-use assets obtained in exchange for operating lease obligations			$ 64.3	$ 54.0
Weighted average remaining lease term - operating leases	6 years 8 months 12 days		6 years 8 months 12 days		6 years 3 months 18 days
Weighted average discount rate - operating leases	4.80%		4.80%		4.60%
Maturities of operating lease liabilities
2025 (remaining six months)	$ 39.8		$ 39.8
2026	71.3		71.3
2027	60.3		60.3
2028	49.9		49.9
2029	41.4		41.4
Thereafter	100.9		100.9
Total operating lease payments	363.6		363.6
Less: imputed interest	(57.0)		(57.0)
Total operating lease liabilities	$ 306.6		$ 306.6