v3.24.0.1
Business Combinations and Asset Acquisitions - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2023
USD ($)
business
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
brokerage
company
Acquisitions
Mar. 31, 2024
USD ($)
Dec. 31, 2020
USD ($)
Business Acquisition [Line Items]          
Contingent consideration liability $ 20,900,000 $ 14,000,000.0 $ 24,400,000   $ 39,800,000
Goodwill 209,800,000 198,400,000 188,300,000    
Payment to acquire business net of cash acquired (700,000) 15,000,000.0 $ 137,400,000    
Number of small real estate brokerages | brokerage     3    
Number of small title insurance and escrow settlement service companies | company     3    
Contingent liabilities undiscounted estimated payment 31,800,000        
Future consideration to be paid to the acquirees 2,900,000        
Compensation expenses, future services $ 600,000 $ 13,400,000 $ 28,600,000    
Minimum | Customer relationships          
Business Acquisition [Line Items]          
Useful life (in years) 2 years 2 years      
Maximum | Customer relationships          
Business Acquisition [Line Items]          
Useful life (in years) 9 years 9 years      
2023 Real Estate Brokerage          
Business Acquisition [Line Items]          
Ownership interest acquired (in percent) 100.00%        
Number of businesses acquired | business 2        
Class A common stock issued $ 6,800,000        
Cash paid at closing 1,100,000        
Recognized identifiable assets and liabilities assumed, other assets 4,700,000        
Recognized identifiable assets and liabilities assumed, other liabilities 6,100,000        
Goodwill 11,400,000        
Goodwill, deductible amount 600,000        
2023 Real Estate Brokerage | Cash Consideration To Be Paid At A Later Date          
Business Acquisition [Line Items]          
Contingent consideration liability 1,000,000        
2023 Real Estate Brokerage | Class A Common Stock And Cash, Earnings -Based Targets          
Business Acquisition [Line Items]          
Contingent consideration liability 14,000,000        
2023 Real Estate Brokerage | Customer relationships          
Business Acquisition [Line Items]          
Recognized identifiable assets and liabilities assumed, intangible assets, other than goodwill $ 10,800,000        
Useful life (in years) 5 years        
2023 Real Estate Brokerage | Forecast          
Business Acquisition [Line Items]          
Goodwill, deductible amount       $ 8,700,000  
Title Insurance and Escrow Settlement Services Company and Real Estate Brokerage          
Business Acquisition [Line Items]          
Ownership interest acquired (in percent)   100.00%      
Recognized identifiable assets and liabilities assumed, other assets   $ 1,000,000      
Recognized identifiable assets and liabilities assumed, other liabilities   2,500,000      
Goodwill   8,800,000      
Goodwill, deductible amount   0      
Payment to acquire business net of cash acquired   12,100,000      
Additional cash payable   $ 3,600,000      
Title Insurance and Escrow Settlement Services Company and Real Estate Brokerage | Forecast          
Business Acquisition [Line Items]          
Goodwill, deductible amount       $ 2,600,000  
Title Insurance and Escrow Settlement Services Company and Real Estate Brokerage | Minimum          
Business Acquisition [Line Items]          
Useful life (in years)   3 years      
Title Insurance and Escrow Settlement Services Company and Real Estate Brokerage | Maximum          
Business Acquisition [Line Items]          
Useful life (in years)   5 years      
Title Insurance and Escrow Settlement Services Company and Real Estate Brokerage | Customer relationships          
Business Acquisition [Line Items]          
Recognized identifiable assets and liabilities assumed, intangible assets, other than goodwill   $ 8,100,000      
Title Insurance and Escrow Settlement Services Company and Real Estate Brokerage | Trademarks          
Business Acquisition [Line Items]          
Recognized identifiable assets and liabilities assumed, intangible assets, other than goodwill   1,100,000      
Title Insurance and Escrow Settlement Services Company and Real Estate Brokerage | Class A common stock          
Business Acquisition [Line Items]          
Class A common stock issued   $ 800,000      
KVS Title LLC          
Business Acquisition [Line Items]          
Ownership interest acquired (in percent)     100.00%    
2021 Real Estate Brokerages          
Business Acquisition [Line Items]          
Payment to acquire business net of cash acquired     $ 13,200,000    
Additional cash payable     $ 3,400,000    
Number of asset acquisitions | Acquisitions     2    
2021 Real Estate Brokerages | Customer relationships          
Business Acquisition [Line Items]          
Recognized identifiable assets and liabilities assumed, intangible assets, other than goodwill     $ 23,900,000    
2021 Real Estate Brokerages | Class A common stock          
Business Acquisition [Line Items]          
Class A common stock issued     $ 5,800,000