Segment Disclosures - Summary of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Revenue	$ 224,238	$ 213,866
Operating expenses	178,117	170,864
Gross margin	46,121	43,002
Corporate general & admin	10,245	9,865
Operating income (loss)	35,876	33,137
Other income (expense):
Interest expense	(1,526)	(2,977)
Gain on sale of operations, net	101	56
Other income, net	2,147	2,859
Total other income (expense)	722	(62)
Income (loss) from continuing operations before income tax expense	36,598	33,075
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue	152,207	143,832
Operating expenses	113,497	108,618
Gross margin	38,710	35,214
Operating income (loss)	38,710	35,214
Other income (expense):
Other income, net	254	99
Total other income (expense)	254	99
Income (loss) from continuing operations before income tax expense	38,964	35,313
Operating Segments [Member] | Employee Services [Member]
Segment Reporting Information [Line Items]
Revenue	64,327	62,651
Operating expenses	53,680	51,528
Gross margin	10,647	11,123
Operating income (loss)	10,647	11,123
Other income (expense):
Interest expense	(10)	(9)
Other income, net	74	117
Total other income (expense)	64	108
Income (loss) from continuing operations before income tax expense	10,711	11,231
Operating Segments [Member] | National Practices [Member]
Segment Reporting Information [Line Items]
Revenue	7,704	7,383
Operating expenses	6,877	6,601
Gross margin	827	782
Operating income (loss)	827	782
Other income (expense):
Income (loss) from continuing operations before income tax expense	827	782
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating expenses	4,063	4,117
Gross margin	(4,063)	(4,117)
Corporate general & admin	10,245	9,865
Operating income (loss)	(14,308)	(13,982)
Other income (expense):
Interest expense	(1,516)	(2,968)
Gain on sale of operations, net	101	56
Other income, net	1,819	2,643
Total other income (expense)	404	(269)
Income (loss) from continuing operations before income tax expense	$ (13,904)	$ (14,251)