Segment Disclosures - Summary of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 241,459	$ 224,238
Operating expenses	192,766	178,117
Gross margin	48,693	46,121
Corporate general & admin	8,768	10,245
Operating income	39,925	35,876
Other income (expense):
Interest expense	(1,517)	(1,526)
Gain on sale of operations, net	22	101
Other income, net	2,737	2,147
Total other income, net	1,242	722
Income from continuing operations before income tax expense	41,167	36,598
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Revenue	158,633	152,207
Operating expenses	119,389	113,497
Gross margin	39,244	38,710
Operating income	39,244	38,710
Other income (expense):
Other income, net	15	254
Total other income, net	15	254
Income from continuing operations before income tax expense	39,259	38,964
Operating Segments [Member] | Benefits and Insurance Services [Member]
Segment Reporting Information [Line Items]
Revenue	75,164	64,327
Operating expenses	60,142	53,680
Gross margin	15,022	10,647
Operating income	15,022	10,647
Other income (expense):
Interest expense	(11)	(10)
Other income, net	96	74
Total other income, net	85	64
Income from continuing operations before income tax expense	15,107	10,711
Operating Segments [Member] | National Practices [Member]
Segment Reporting Information [Line Items]
Revenue	7,662	7,704
Operating expenses	7,007	6,877
Gross margin	655	827
Operating income	655	827
Other income (expense):
Income from continuing operations before income tax expense	655	827
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating expenses	6,228	4,063
Gross margin	(6,228)	(4,063)
Corporate general & admin	8,768	10,245
Operating income	(14,996)	(14,308)
Other income (expense):
Interest expense	(1,506)	(1,516)
Gain on sale of operations, net	22	101
Other income, net	2,626	1,819
Total other income, net	1,142	404
Income from continuing operations before income tax expense	$ (13,854)	$ (13,904)