Segment Disclosures - Summary of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenue	$ 178,785	$ 199,794	$ 197,015	$ 224,238	$ 164,412		$ 187,102		$ 185,042		$ 213,866		$ 799,832	$ 750,422		$ 719,483
Operating expenses	171,544	174,069	173,996	178,117	159,914	[1]	158,496	[1]	163,117	[1]	170,864	[1]	697,726	652,391	[2]	629,804
Gross margin	7,241	25,725	23,019	46,121	4,498		28,606		21,925		43,002		102,106	98,031		89,679
Corporate general and administrative expenses	9,049	8,679	8,346	10,245	8,019	[1]	8,028	[1]	6,615	[1]	9,865	[1]	36,319	32,527	[2]	34,183
Operating income (loss)	(1,808)	17,046	14,673	35,876	(3,521)		20,578		15,310		33,137		65,787	65,504		55,496
Other income (expense):
Interest expense													(6,593)	(8,902)		(13,124)
Gain on sale of operations, net	375	329	50	101	(22)		5		45		56		855	84		1,303
Other income, net	1,475	2,632	703	2,147	1,780	[1]	(2,367)	[1]	(1,126)	[1]	2,859	[1]	6,957	1,146	[2]	6,893
Total other income (expense), net	$ 276	$ 1,201	$ (980)	$ 722	$ 521		$ (4,202)		$ (3,929)		$ (62)		1,219	(7,672)		(4,928)
Income from continuing operations before income tax expense													67,006	57,832		50,568
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue													501,307	476,396		465,130
Operating expenses													432,254	411,325	[2]	399,783
Gross margin													69,053	65,071		65,347
Operating income (loss)													69,053	65,071		65,347
Other income (expense):
Other income, net													209	(147)	[2]	417
Total other income (expense), net													209	(147)		417
Income from continuing operations before income tax expense													69,262	64,924		65,764
Operating Segments [Member] | Benefits and Insurance Services [Member]
Segment Reporting Information [Line Items]
Revenue													267,606	244,493		224,898
Operating expenses													223,487	202,138	[2]	186,002
Gross margin													44,119	42,355		38,896
Operating income (loss)													44,119	42,355		38,896
Other income (expense):
Interest expense													(39)	(35)		(31)
Other income, net													367	467	[2]	557
Total other income (expense), net													328	432		526
Income from continuing operations before income tax expense													44,447	42,787		39,422
Operating Segments [Member] | National Practices [Member]
Segment Reporting Information [Line Items]
Revenue													30,919	29,533		29,455
Operating expenses													27,697	26,417	[2]	26,798
Gross margin													3,222	3,116		2,657
Operating income (loss)													3,222	3,116		2,657
Other income (expense):
Other income, net													3	4	[2]	4
Total other income (expense), net													3	4		4
Income from continuing operations before income tax expense													3,225	3,120		2,661
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating expenses													14,288	12,511	[2]	17,221
Gross margin													(14,288)	(12,511)		(17,221)
Corporate general and administrative expenses													36,319	32,527	[2]	34,183
Operating income (loss)													(50,607)	(45,038)		(51,404)
Other income (expense):
Interest expense													(6,554)	(8,867)		(13,093)
Gain on sale of operations, net													855	84		1,303
Other income, net													6,378	822	[2]	5,915
Total other income (expense), net													679	(7,961)		(5,875)
Income from continuing operations before income tax expense													$ (49,928)	$ (52,999)		$ (57,279)

[1] “Operating expenses” and “Corporate general and administrative expenses” include a reduction ($1.6 million and less than $0.1 million) related to a state payroll tax incentive associated with an office relocation. The reduction was recorded in “Other (expense) income, net” beginning in the third quarter of 2015, but was reclassified to “Operating expenses” and “Corporate general and administrative expenses” to align the incentives with the expenses associated with the office relocation. The reclassification had no impact on “Income from continuing operations” or diluted earnings per share from continuing operations.

[2] “Operating expenses” under the Financial Services and Benefits and Insurance Services practice groups include a reduction of $0.9 million and $0.6 million related to a state payroll tax incentive associated with an office relocation. “Corporate general and administrative expenses” include a reduction of less than $0.1 million related to the office relocation as discussed above. The reductions was recorded in “Other (expense) income, net” in 2015 but was reclassified to “Operating expenses” and “Corporate general and administrative expenses” to align the incentives with the expenses associated with the office relocation. The reclassification had no impact on “Income from continuing operations” or diluted earnings per share from continuing operations.