v3.25.2
Acquisitions - Additional Information (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended 6 Months Ended 12 Months Ended
Jan. 13, 2025
Sep. 30, 2025
Mar. 31, 2025
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Business Combination [Line Items]            
Payments for acquisitions, net of cash acquired       $ 172.0 $ 18.0  
Undiscounted estimated payment       31.9    
Christie's International Real Estate            
Business Combination [Line Items]            
Cash consideration $ 153.0          
Equity interest issued or issuable (in shares) 44.1          
Post-closing share price calculation period, trading days 10 days          
Post-closing share price threshold, purchase price adjustment $ 344.0          
Post-closing share adjustment, maximum dollar value affected $ 50.0          
Post-closing share adjustment, maximum shares affected (in shares) 5.6          
Post-closing share price floor, purchase price adjustment (in dollars per share) $ 6.6612          
Post-closing share adjustment, maximum shares issuable (in shares) 7.5          
Share consideration $ 250.1          
Goodwill, expected tax deductible amount       0.0    
Goodwill, possible increase in expected tax deductible amount       $ 212.0    
Transaction related costs 5.0   $ 0.7     $ 4.3
Christie's International Real Estate | Legal Fees            
Business Combination [Line Items]            
Transaction related costs 3.4          
Christie's International Real Estate | Professional And General Consulting Fees            
Business Combination [Line Items]            
Transaction related costs $ 1.6          
Residential Real Estate Brokerage            
Business Combination [Line Items]            
Ownership interest acquired (as percent)       100.00%    
Residential Real Estate Brokerage, Title Insurance And Escrow Settlement Business            
Business Combination [Line Items]            
Payments for acquisitions, net of cash acquired       $ 23.6    
Residential Real Estate Brokerage, Title Insurance And Escrow Settlement Business | Forecast            
Business Combination [Line Items]            
Payments for acquisitions, net of cash acquired   $ 3.0        
Residential Real Estate Brokerage, Title Insurance And Escrow Settlement Business | Customer Relationships            
Business Combination [Line Items]            
Fair value of assets acquired and liabilities assumed recognized       $ 15.7    
Estimated useful life (in years)       4 years