Quarterly Financial Data (Unaudited) - Summary of Unaudited Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ 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
Quarterly Financial Information Disclosure [Abstract]
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	(1,574)	(1,760)	(1,733)	(1,526)	(1,237)		(1,840)		(2,848)		(2,977)
Gain (loss) on sale of operations, net	375	329	50	101	(22)		5		45		56		855	84		1,303
Other income (loss), 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 (loss) from continuing operations before income tax expense (benefit)	(1,532)	18,247	13,693	36,598	(3,000)		16,376		11,381		33,075		67,006	57,832		50,568
Income tax expense (benefit)	(967)	7,260	5,306	14,800	(2,226)		6,787		4,696		13,572		26,399	22,829		20,154
Income (loss) from continuing operations	(565)	10,987	8,387	21,798	(774)		9,589		6,685		19,503		40,607	35,003		30,414
Loss from operations of discontinued operations, net of tax	(121)	(133)	(258)	(30)	(1,097)		(561)		(330)		(335)		(542)	(2,323)		(754)
Gain (loss) on disposal of discontinued operations, net of tax					(35)		1,172		290					1,427		99
Net income (loss)	$ (686)	$ 10,854	$ 8,129	$ 21,768	$ (1,906)		$ 10,200		$ 6,645		$ 19,168		$ 40,065	$ 34,107		$ 29,759
Basic:
Continuing operations	$ (0.01)	$ 0.21	$ 0.16	$ 0.42	$ (0.02)		$ 0.19		$ 0.14		$ 0.41		$ 0.78	$ 0.70		$ 0.63
Discontinued operations					(0.01)		0.01		(0.01)		(0.01)		(0.01)	(0.01)		(0.01)
Net income	(0.01)	0.21	0.16	0.42	(0.03)		0.20		0.13		0.40		0.77	0.69		0.62
Diluted:
Continuing operations	(0.01)	0.20	0.16	0.41	(0.02)		0.18		0.13		0.38		0.76	0.66		0.59
Discontinued operations					(0.02)		0.01				(0.01)		(0.01)	(0.01)		(0.01)
Net income	$ (0.01)	$ 0.20	$ 0.16	$ 0.41	$ (0.04)		$ 0.19		$ 0.13		$ 0.37		$ 0.75	$ 0.65		$ 0.58
Basic weighted average common shares	53,019	52,648	52,031	51,572	51,669		51,736		49,464		48,146		52,321	50,280		48,343
Diluted weighted average common shares	53,019	53,846	53,079	52,745	51,669		54,445		52,024		51,385		53,513	52,693		51,487

[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.