v3.26.1
BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details)
 3 Months Ended 12 Months Ended
Oct. 31, 2025
reporting_unit
Dec. 31, 2025
USD ($)
Dec. 31, 2025
USD ($)
practice_group
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Summary Of Significant Accounting Policies [Line Items]            
Number of practice groups | practice_group     2      
Revenue     $ 2,757,991,000 $ 1,813,472,000 $ 1,591,194,000  
Notes receivable   $ 21,700,000 $ 21,700,000 22,200,000    
Maximum maturity period of investments     3 months      
Allowance for doubtful accounts   49,915,000 $ 49,915,000 31,715,000 25,598,000 $ 20,801,000
Goodwill   2,329,799,000 2,329,799,000 2,331,461,000 865,180,000  
Assets   4,409,528,000 4,409,528,000 4,470,883,000    
Total stockholders' equity   1,762,067,000 $ 1,762,067,000 1,779,983,000 791,618,000 $ 713,452,000
Number of reporting units | reporting_unit 5          
Goodwill impairment   $ 0        
Intangible assets amortization period   8 years 3 months 18 days 8 years 3 months 18 days      
Adjustment to contingent earnout liability, net     $ 2,588,000 6,993,000 2,743,000  
Unsecured credit facility   $ 2,000,000,000 2,000,000,000      
Other income (expense), net            
Summary Of Significant Accounting Policies [Line Items]            
Adjustment to contingent earnout liability, net     (2,600,000) (7,000,000.0) (2,700,000)  
Financial Services            
Summary Of Significant Accounting Policies [Line Items]            
Revenue     2,348,358,000 1,412,424,000 1,208,589,000  
Goodwill   1,997,294,000 1,997,294,000 2,001,232,000 548,856,000  
Number of reporting units | reporting_unit 3          
Benefits and Insurance Services            
Summary Of Significant Accounting Policies [Line Items]            
Revenue     409,633,000 401,048,000 382,605,000  
Goodwill   $ 332,505,000 $ 332,505,000 330,229,000 316,324,000  
Number of reporting units | reporting_unit 2          
Minimum            
Summary Of Significant Accounting Policies [Line Items]            
Shares vesting term     2 years      
Intangible assets amortization period   3 years 3 years      
Minimum | Capitalized software            
Summary Of Significant Accounting Policies [Line Items]            
Property and equipment useful life   3 years 3 years      
Maximum            
Summary Of Significant Accounting Policies [Line Items]            
Shares vesting term     4 years      
Intangible assets amortization period   15 years 15 years      
Maximum | Capitalized software            
Summary Of Significant Accounting Policies [Line Items]            
Property and equipment useful life   5 years 5 years      
Financial service            
Summary Of Significant Accounting Policies [Line Items]            
Revenue     $ 651,200,000 $ 306,500,000 $ 259,600,000