SEGMENT DISCLOSURES - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Revenue	$ 420,012	$ 398,502	$ 914,309	$ 853,108
Operating expenses (income)	366,368	343,987	742,853	684,998
Gross margin	53,644	54,515	171,456	168,110
Corporate general and administrative expenses	22,050	15,793	40,761	31,391
Operating income	31,594	38,722	130,695	136,719
Other income (expense):
Interest expense	(5,884)	(5,534)	(10,395)	(9,175)
Gain on sale of operations, net	0	0	0	99
Other income, net	2,483	5,421	11,907	10,533
Total other (expense) income, net	(3,401)	(113)	1,512	1,457
Income before income tax expense	28,193	38,609	132,207	138,176
Financial Services
Segment Reporting Information [Line Items]
Revenue	309,233	290,930	681,863	634,016
Benefits and Insurance Services
Segment Reporting Information [Line Items]
Revenue	97,419	95,838	205,827	195,892
National Practices
Segment Reporting Information [Line Items]
Revenue	13,360	11,734	26,619	23,200
Operating Segments | Financial Services
Segment Reporting Information [Line Items]
Revenue	309,233	290,930	681,863	634,016
Operating expenses (income)	262,809	243,445	528,370	487,888
Gross margin	46,424	47,485	153,493	146,128
Corporate general and administrative expenses	0	0	0	0
Operating income	46,424	47,485	153,493	146,128
Other income (expense):
Interest expense	0	0	0	0
Gain on sale of operations, net				99
Other income, net	128	235	214	490
Total other (expense) income, net	128	235	214	589
Income before income tax expense	46,552	47,720	153,707	146,717
Operating Segments | Benefits and Insurance Services
Segment Reporting Information [Line Items]
Revenue	97,419	95,838	205,827	195,892
Operating expenses (income)	83,243	78,374	166,880	155,297
Gross margin	14,176	17,464	38,947	40,595
Corporate general and administrative expenses	0	0	0	0
Operating income	14,176	17,464	38,947	40,595
Other income (expense):
Interest expense	0	0	0	(1)
Gain on sale of operations, net				0
Other income, net	43	153	87	330
Total other (expense) income, net	43	153	87	329
Income before income tax expense	14,219	17,617	39,034	40,924
Operating Segments | National Practices
Segment Reporting Information [Line Items]
Revenue	13,360	11,734	26,619	23,200
Operating expenses (income)	12,028	10,545	23,961	21,128
Gross margin	1,332	1,189	2,658	2,072
Corporate general and administrative expenses	0	0	0	0
Operating income	1,332	1,189	2,658	2,072
Other income (expense):
Interest expense	0	0	0	0
Gain on sale of operations, net				0
Other income, net	(4)	1	(4)	1
Total other (expense) income, net	(4)	1	(4)	1
Income before income tax expense	1,328	1,190	2,654	2,073
Corporate and Other
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Operating expenses (income)	8,288	11,623	23,642	20,685
Gross margin	(8,288)	(11,623)	(23,642)	(20,685)
Corporate general and administrative expenses	22,050	15,793	40,761	31,391
Operating income	(30,338)	(27,416)	(64,403)	(52,076)
Other income (expense):
Interest expense	(5,884)	(5,534)	(10,395)	(9,174)
Gain on sale of operations, net				0
Other income, net	2,316	5,032	11,610	9,712
Total other (expense) income, net	(3,568)	(502)	1,215	538
Income before income tax expense	$ (33,906)	$ (27,918)	$ (63,188)	$ (51,538)