SEGMENT DISCLOSURES - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Revenue	$ 438,884	$ 410,539	$ 1,353,193	$ 1,263,647
Operating expenses	365,971	342,148	1,108,824	1,027,146
Gross margin	72,913	68,391	244,369	236,501
Corporate general and administrative expenses	23,227	13,136	63,988	44,527
Operating income	49,686	55,255	180,381	191,974
Other income (expense):
Interest expense	(4,968)	(5,848)	(15,363)	(15,023)
Gain on sale of operations, net	4,953	77	4,953	176
Other income, net	1,300	(2,288)	13,207	8,245
Total other income (expense), net	1,285	(8,059)	2,797	(6,602)
Income before income tax expense	50,971	47,196	183,178	185,372
Financial Services
Segment Reporting Information [Line Items]
Revenue	322,295	298,372	1,004,158	932,388
Benefits and Insurance Services
Segment Reporting Information [Line Items]
Revenue	104,040	100,287	309,867	296,179
National Practices
Segment Reporting Information [Line Items]
Revenue	12,549	11,880	39,168	35,080
Operating Segments | Financial Services
Segment Reporting Information [Line Items]
Revenue	322,295	298,372	1,004,158	932,388
Operating expenses	260,639	249,680	789,009	737,568
Gross margin	61,656	48,692	215,149	194,820
Corporate general and administrative expenses	0	0	0	0
Operating income	61,656	48,692	215,149	194,820
Other income (expense):
Interest expense	0	0	0	0
Gain on sale of operations, net	0	77	0	176
Other income, net	15	1,497	229	1,987
Total other income (expense), net	15	1,574	229	2,163
Income before income tax expense	61,671	50,266	215,378	196,983
Operating Segments | Benefits and Insurance Services
Segment Reporting Information [Line Items]
Revenue	104,040	100,287	309,867	296,179
Operating expenses	82,965	79,636	249,845	234,933
Gross margin	21,075	20,651	60,022	61,246
Corporate general and administrative expenses	0	0	0	0
Operating income	21,075	20,651	60,022	61,246
Other income (expense):
Interest expense	(3)	0	(3)	(1)
Gain on sale of operations, net	0	0	0	0
Other income, net	5	267	92	597
Total other income (expense), net	2	267	89	596
Income before income tax expense	21,077	20,918	60,111	61,842
Operating Segments | National Practices
Segment Reporting Information [Line Items]
Revenue	12,549	11,880	39,168	35,080
Operating expenses	11,101	10,667	35,062	31,795
Gross margin	1,448	1,213	4,106	3,285
Corporate general and administrative expenses	0	0	0	0
Operating income	1,448	1,213	4,106	3,285
Other income (expense):
Interest expense	0	0	0	0
Gain on sale of operations, net	4,953	0	4,953	0
Other income, net	0	0	(4)	1
Total other income (expense), net	4,953	0	4,949	1
Income before income tax expense	6,401	1,213	9,055	3,286
Corporate and Other
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Operating expenses	11,266	2,165	34,908	22,850
Gross margin	(11,266)	(2,165)	(34,908)	(22,850)
Corporate general and administrative expenses	23,227	13,136	63,988	44,527
Operating income	(34,493)	(15,301)	(98,896)	(67,377)
Other income (expense):
Interest expense	(4,965)	(5,848)	(15,360)	(15,022)
Gain on sale of operations, net	0	0	0	0
Other income, net	1,280	(4,052)	12,890	5,660
Total other income (expense), net	(3,685)	(9,900)	(2,470)	(9,362)
Income before income tax expense	$ (38,178)	$ (25,201)	$ (101,366)	$ (76,739)