Segment Disclosures - Summary of Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenue	$ 1,591,194	$ 1,411,979	$ 1,104,925
Operating expenses	1,367,990	1,188,612	945,635
Gross margin	223,204	223,367	159,290
Corporate general and administrative expenses	57,965	55,023	56,150
Legal settlement, net	0	0	30,468
Operating income	165,239	168,344	72,672
Other income (expense):
Interest expense	(20,131)	(8,039)	(3,868)
(Loss) gain on sale of operations, net	176	413	5,995
Other income, net	21,019	(19,243)	18,217
Total other income (expense), net	1,064	(26,869)	20,344
Income before income tax expense	166,303	141,475	93,016
Financial Services
Segment Reporting Information [Line Items]
Revenue	1,160,686	1,010,068	734,026
Benefits and Insurance Services
Segment Reporting Information [Line Items]
Revenue	382,605	358,007	332,323
National Practices
Segment Reporting Information [Line Items]
Revenue	47,903	43,904	38,576
Operating Segments | Financial Services
Segment Reporting Information [Line Items]
Revenue	1,160,686	1,010,068	734,026
Operating expenses	975,076	850,038	608,238
Gross margin	185,610	160,030	125,788
Corporate general and administrative expenses	0	0	0
Legal settlement, net			0
Operating income	185,610	160,030	125,788
Other income (expense):
Interest expense	0	0	0
(Loss) gain on sale of operations, net	176	413	(289)
Other income, net	2,042	269	263
Total other income (expense), net	2,218	682	(26)
Income before income tax expense	187,828	160,712	125,762
Operating Segments | Benefits and Insurance Services
Segment Reporting Information [Line Items]
Revenue	382,605	358,007	332,323
Operating expenses	310,510	290,387	271,650
Gross margin	72,095	67,620	60,673
Corporate general and administrative expenses	0	0	0
Legal settlement, net			0
Operating income	72,095	67,620	60,673
Other income (expense):
Interest expense	(2)	(6)	0
(Loss) gain on sale of operations, net	0	0	6,284
Other income, net	2,060	2,392	827
Total other income (expense), net	2,058	2,386	7,111
Income before income tax expense	74,153	70,006	67,784
Operating Segments | National Practices
Segment Reporting Information [Line Items]
Revenue	47,903	43,904	38,576
Operating expenses	43,060	39,201	34,494
Gross margin	4,843	4,703	4,082
Corporate general and administrative expenses	0	0	0
Legal settlement, net			0
Operating income	4,843	4,703	4,082
Other income (expense):
Interest expense	0	0	0
(Loss) gain on sale of operations, net	0	0	0
Other income, net	1	10	3
Total other income (expense), net	1	10	3
Income before income tax expense	4,844	4,713	4,085
Corporate and Other
Segment Reporting Information [Line Items]
Revenue	0	0	0
Operating expenses	39,344	8,986	31,253
Gross margin	(39,344)	(8,986)	(31,253)
Corporate general and administrative expenses	57,965	55,023	56,150
Legal settlement, net			30,468
Operating income	(97,309)	(64,009)	(117,871)
Other income (expense):
Interest expense	(20,129)	(8,033)	(3,868)
(Loss) gain on sale of operations, net	0	0	0
Other income, net	16,916	(21,914)	17,124
Total other income (expense), net	(3,213)	(29,947)	13,256
Income before income tax expense	$ (100,522)	$ (93,956)	$ (104,615)