Segment Disclosures - Summary of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenue	$ 238,389	$ 239,790	$ 752,787	$ 745,286
Operating expenses	204,760	209,146	613,603	622,790
Gross margin	33,629	30,644	139,184	122,496
Corporate general & admin	11,339	11,670	32,988	33,916
Operating income	22,290	18,974	106,196	88,580
Other income (expense):
Interest expense	(974)	(1,521)	(4,167)	(4,509)
Gain (loss) on sale of operations, net	(74)	(145)	78	402
Other (expense) income, net	5,914	6,767	3,450	12,716
Total other income (expense), net	4,866	5,101	(639)	8,609
Income from continuing operations before income tax expense	27,156	24,075	105,557	97,189
Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue	155,499	153,794	498,359	493,311
Benefits and Insurance Services [Member]
Segment Reporting Information [Line Items]
Revenue	73,881	76,960	227,433	225,342
National Practices [Member]
Segment Reporting Information [Line Items]
Revenue	9,009	9,036	26,995	26,633
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue	155,499	153,794	498,359	493,311
Operating expenses	129,922	128,231	395,937	390,847
Gross margin	25,577	25,563	102,422	102,464
Operating income	25,577	25,563	102,422	102,464
Other income (expense):
Gain (loss) on sale of operations, net	(76)	16	(25)	563
Other (expense) income, net	(14)	14	32	(188)
Total other income (expense), net	(90)	30	7	375
Income from continuing operations before income tax expense	25,487	25,593	102,429	102,839
Operating Segments [Member] | Benefits and Insurance Services [Member]
Segment Reporting Information [Line Items]
Revenue	73,881	76,960	227,433	225,342
Operating expenses	62,013	63,390	188,519	185,836
Gross margin	11,868	13,570	38,914	39,506
Operating income	11,868	13,570	38,914	39,506
Other income (expense):
Interest expense	(10)	(14)	(30)	(38)
Gain (loss) on sale of operations, net	2		103
Other (expense) income, net	(36)	9	190	204
Total other income (expense), net	(44)	(5)	263	166
Income from continuing operations before income tax expense	11,824	13,565	39,177	39,672
Operating Segments [Member] | National Practices [Member]
Segment Reporting Information [Line Items]
Revenue	9,009	9,036	26,995	26,633
Operating expenses	8,070	8,104	24,343	24,308
Gross margin	939	932	2,652	2,325
Operating income	939	932	2,652	2,325
Other income (expense):
Other (expense) income, net			1	1
Total other income (expense), net	0	0	1	1
Income from continuing operations before income tax expense	939	932	2,653	2,326
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating expenses	4,755	9,421	4,804	21,799
Gross margin	(4,755)	(9,421)	(4,804)	(21,799)
Corporate general & admin	11,339	11,670	32,988	33,916
Operating income	(16,094)	(21,091)	(37,792)	(55,715)
Other income (expense):
Interest expense	(964)	(1,507)	(4,137)	(4,471)
Gain (loss) on sale of operations, net		(161)		(161)
Other (expense) income, net	5,964	6,744	3,227	12,699
Total other income (expense), net	5,000	5,076	(910)	8,067
Income from continuing operations before income tax expense	$ (11,094)	$ (16,015)	$ (38,702)	$ (47,648)