v3.25.3
SEGMENT DISCLOSURES - Summary of Segment Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Segment Reporting Information [Line Items]        
Revenue $ 693,818 $ 438,884 $ 2,215,328 $ 1,353,193
Corporate & other:        
General & administrative expenses 31,265 23,227 86,972 63,988
Interest expense 27,960 4,968 80,983 15,363
Other income, net (8,378) (1,300) (31,786) (13,207)
Income before income tax expense 40,406 50,971 271,095 183,178
Operating Segments        
Segment Reporting Information [Line Items]        
Revenue 693,818 438,884 2,215,328 1,353,193
Personnel costs 456,888 285,916 1,398,713 869,520
Facility costs 26,158 15,114 79,912 45,328
Other costs, gains, and losses, net 95,015 48,705 283,966 153,801
Total segment expense 578,061 349,735 1,762,591 1,068,649
Corporate & other:        
Income before income tax expense 115,757 89,149 452,737 284,544
Operating Segments | Financial Services        
Segment Reporting Information [Line Items]        
Revenue 578,522 322,295 1,862,002 1,004,158
Personnel costs 381,106 210,418 1,170,676 640,021
Facility costs 22,937 11,962 70,283 35,807
Other costs, gains, and losses, net 80,417 38,244 238,293 112,952
Total segment expense 484,460 260,624 1,479,252 788,780
Corporate & other:        
Income before income tax expense 94,062 61,671 382,750 215,378
Operating Segments | Benefits and Insurance Services        
Segment Reporting Information [Line Items]        
Revenue 103,387 104,040 318,292 309,867
Personnel costs 65,222 64,855 196,965 196,013
Facility costs 3,219 3,110 9,622 9,354
Other costs, gains, and losses, net 15,599 14,998 46,445 44,389
Total segment expense 84,040 82,963 253,032 249,756
Corporate & other:        
Income before income tax expense 19,347 21,077 65,260 60,111
Operating Segments | National Practices        
Segment Reporting Information [Line Items]        
Revenue 11,909 12,549 35,034 39,168
Personnel costs 10,560 10,643 31,072 33,486
Facility costs 2 42 7 167
Other costs, gains, and losses, net (1,001) (4,537) (772) (3,540)
Total segment expense 9,561 6,148 30,307 30,113
Corporate & other:        
Income before income tax expense 2,348 6,401 4,727 9,055
Corporate And Eliminations        
Corporate & other:        
Unallocated corporate operating expenses 25,081 11,266 45,518 34,908
General & administrative expenses 31,265 23,227 86,972 63,988
Interest expense 27,960 4,968 80,983 15,363
Other income, net $ (8,955) $ (1,283) $ (31,831) $ (12,893)