v3.26.1
Equity Method Investments in Affiliates - Additional Information (Details)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
affiliate
Mar. 31, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
affiliate
Jun. 30, 2025
USD ($)
Dec. 31, 2025
affiliate
Schedule of Equity Method Investments [Line Items]            
Number of affiliates | affiliate 24     24   22
Consolidated revenue $ 640.7   $ 493.2 $ 1,185.6 $ 989.8  
Net income 237.4   135.9 383.7 235.1  
Acquired Client Relationships            
Schedule of Equity Method Investments [Line Items]            
Amortization of intangible assets 7.2   6.3 13.5 12.6  
Estimated Future Amortization Expense of Finite-Lived Intangibles            
Intangible future amortization expense remainder of fiscal year 15.0     15.0    
Intangible future amortization expense in year one 25.0     25.0    
Intangible future amortization expense in year two 25.0     25.0    
Intangible future amortization expense in year three 15.0     15.0    
Intangible future amortization expense in year four 10.0     10.0    
Intangible future amortization expense in year five 10.0     10.0    
Equity Method Investee            
Schedule of Equity Method Investments [Line Items]            
Consolidated revenue       901.0 403.6  
Net income       642.8 198.0  
Estimated Future Amortization Expense of Finite-Lived Intangibles            
Impairment expense   $ 8.0        
Equity Method Investee | Acquired Client Relationships            
Schedule of Equity Method Investments [Line Items]            
Amortization of intangible assets 29.2   $ 27.0 55.9 $ 45.6  
Estimated Future Amortization Expense of Finite-Lived Intangibles            
Intangible future amortization expense remainder of fiscal year 60.0     60.0    
Intangible future amortization expense in year one 115.0     115.0    
Intangible future amortization expense in year two 105.0     105.0    
Intangible future amortization expense in year three 90.0     90.0    
Intangible future amortization expense in year four 90.0     90.0    
Intangible future amortization expense in year five $ 90.0     $ 90.0