Segment Disclosures - Summary of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenue	$ 236,943	$ 235,498	$ 514,398	$ 505,496
Operating expenses	209,016	198,148	408,843	413,644
Gross margin	27,927	37,350	105,555	91,852
Corporate general & admin	11,160	10,566	21,649	22,246
Operating income	16,767	26,784	83,906	69,606
Other income (expense):
Interest expense	(2,074)	(1,587)	(3,193)	(2,988)
Gain on sale of operations, net	57	50	152	547
Other income (expense), net	13,336	(3,311)	(2,464)	5,949
Total other income (expense), net	11,319	(4,848)	(5,505)	3,508
Income from continuing operations before income tax expense	28,086	21,936	78,401	73,114
Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue	154,083	154,373	342,860	339,517
Benefits and Insurance Services [Member]
Segment Reporting Information [Line Items]
Revenue	73,940	72,127	153,552	148,382
National Practices [Member]
Segment Reporting Information [Line Items]
Revenue	8,920	8,998	17,986	17,597
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue	154,083	154,373	342,860	339,517
Operating expenses	127,417	128,158	266,015	262,616
Gross margin	26,666	26,215	76,845	76,901
Operating income	26,666	26,215	76,845	76,901
Other income (expense):
Gain on sale of operations, net	11	50	51	547
Other income (expense), net	27	(66)	46	(202)
Total other income (expense), net	38	(16)	97	345
Income from continuing operations before income tax expense	26,704	26,199	76,942	77,246
Operating Segments [Member] | Benefits and Insurance Services [Member]
Segment Reporting Information [Line Items]
Revenue	73,940	72,127	153,552	148,382
Operating expenses	61,283	61,075	126,506	122,446
Gross margin	12,657	11,052	27,046	25,936
Operating income	12,657	11,052	27,046	25,936
Other income (expense):
Interest expense	(9)	(14)	(20)	(24)
Gain on sale of operations, net	46		101
Other income (expense), net	130	174	226	195
Total other income (expense), net	167	160	307	171
Income from continuing operations before income tax expense	12,824	11,212	27,353	26,107
Operating Segments [Member] | National Practices [Member]
Segment Reporting Information [Line Items]
Revenue	8,920	8,998	17,986	17,597
Operating expenses	7,990	8,204	16,273	16,204
Gross margin	930	794	1,713	1,393
Operating income	930	794	1,713	1,393
Other income (expense):
Other income (expense), net		1	1	1
Total other income (expense), net		1	1	1
Income from continuing operations before income tax expense	930	795	1,714	1,394
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating expenses	12,326	711	49	12,378
Gross margin	(12,326)	(711)	(49)	(12,378)
Corporate general & admin	11,160	10,566	21,649	22,246
Operating income	(23,486)	(11,277)	(21,698)	(34,624)
Other income (expense):
Interest expense	(2,065)	(1,573)	(3,173)	(2,964)
Other income (expense), net	13,179	(3,420)	(2,737)	5,955
Total other income (expense), net	11,114	(4,993)	(5,910)	2,991
Income from continuing operations before income tax expense	$ (12,372)	$ (16,270)	$ (27,608)	$ (31,633)