Segment Disclosures - Summary of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 235,498	$ 232,641	$ 505,496	$ 498,731
Operating expenses	198,148	205,102	413,644	409,852
Gross margin	37,350	27,539	91,852	88,879
Corporate general & admin	10,566	9,993	22,246	20,021
Operating income	26,784	17,546	69,606	68,858
Other (expense) income:
Interest expense	(1,587)	(1,817)	(2,988)	(3,597)
Gain on sale of operations, net	50		547	663
Other (expense) income, net	(3,311)	630	5,949	(599)
Total other (expense) income, net	(4,848)	(1,187)	3,508	(3,533)
Income from continuing operations before income tax expense	21,936	16,359	73,114	65,325
Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue	154,373	151,737	339,517	332,340
Benefits and Insurance Services [Member]
Segment Reporting Information [Line Items]
Revenue	72,127	72,753	148,382	150,083
National Practices [Member]
Segment Reporting Information [Line Items]
Revenue	8,998	8,151	17,597	16,308
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue	154,373	151,737	339,517	332,340
Operating expenses	128,158	129,070	262,616	262,103
Gross margin	26,215	22,667	76,901	70,237
Operating income	26,215	22,667	76,901	70,237
Other (expense) income:
Gain on sale of operations, net	50		547
Other (expense) income, net	(66)	(17)	(202)	248
Total other (expense) income, net	(16)	(17)	345	248
Income from continuing operations before income tax expense	26,199	22,650	77,246	70,485
Operating Segments [Member] | Benefits and Insurance Services [Member]
Segment Reporting Information [Line Items]
Revenue	72,127	72,753	148,382	150,083
Operating expenses	61,075	61,165	122,446	122,298
Gross margin	11,052	11,588	25,936	27,785
Operating income	11,052	11,588	25,936	27,785
Other (expense) income:
Interest expense	(14)	(15)	(24)	(89)
Other (expense) income, net	174	30	195	222
Total other (expense) income, net	160	15	171	133
Income from continuing operations before income tax expense	11,212	11,603	26,107	27,918
Operating Segments [Member] | National Practices [Member]
Segment Reporting Information [Line Items]
Revenue	8,998	8,151	17,597	16,308
Operating expenses	8,204	7,567	16,204	14,842
Gross margin	794	584	1,393	1,466
Operating income	794	584	1,393	1,466
Other (expense) income:
Other (expense) income, net	1		1
Total other (expense) income, net	1		1
Income from continuing operations before income tax expense	795	584	1,394	1,466
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating expenses	711	7,300	12,378	10,609
Gross margin	(711)	(7,300)	(12,378)	(10,609)
Corporate general & admin	10,566	9,993	22,246	20,021
Operating income	(11,277)	(17,293)	(34,624)	(30,630)
Other (expense) income:
Interest expense	(1,573)	(1,802)	(2,964)	(3,508)
Gain on sale of operations, net				663
Other (expense) income, net	(3,420)	617	5,955	(1,069)
Total other (expense) income, net	(4,993)	(1,185)	2,991	(3,914)
Income from continuing operations before income tax expense	$ (16,270)	$ (18,478)	$ (31,633)	$ (34,544)