Leases - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Lessee, Lease, Description
Operating lease, liability, including sublease receivables	$ 608,400,000		$ 598,300,000
Operating lease, liability	596,570,000
Operating lease, liability, portion ring-fenced by special purpose vehicles	20,500,000		22,600,000
Operating lease, liability, portion ring-fenced excluding special purpose vehicles	10,000,000.0		10,200,000
Operating lease, future contracted revenues and sublease income	177,100,000		$ 158,200,000
Operating lease costs	33,800,000	$ 33,500,000
Operating lease payments	33,800,000	31,800,000
Short-term lease expense	300,000	400,000
Sublease income	900,000	600,000
Lease impairment	$ 0	0
Weighted average discount rate	5.14%		5.02%
Weighted average lease term	6 years 7 months 6 days		5 years 8 months 12 days
Right-of-use assets	$ 513,383,000		$ 500,464,000
Right-of-use liabilities	$ 106,112,000		$ 108,434,000
Operating lease, liability, current, statement of financial position flag	Accounts payable, accrued expenses and other liabilities (see Note 25)		Accounts payable, accrued expenses and other liabilities (see Note 25)
Right-of-use liabilities, non-current	$ 502,331,000		$ 489,832,000
Rent expense	41,900,000	$ 41,700,000
Management services, servicing fees and other
Lessee, Lease, Description
Operating lease, liability	$ 137,500,000		$ 151,100,000
Minimum
Lessee, Lease, Description
Remaining lease terms	1 year
Options to extend leases	1 year
Maximum
Lessee, Lease, Description
Remaining lease terms	17 years
Options to extend leases	10 years