Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net service revenues	$ 864,499	$ 764,775	$ 648,791
Cost of service revenues	594,651	538,538	469,553
Gross profit	269,848	226,237	179,238
General and administrative expenses	189,418	169,679	133,912
Depreciation and amortization	14,494	12,051	10,574
Total operating expenses	203,912	181,730	144,486
Operating income from continuing operations	65,936	44,507	34,752
Interest income	(268)	(624)	(1,523)
Interest expense	5,806	3,189	3,105
Total interest expense, net	5,538	2,565	1,582
Income from continuing operations before income taxes	60,398	41,942	33,170
Income tax expense	15,272	8,809	7,359
Net income from continuing operations	45,126	33,133	25,811
Loss from discontinued operations			(574)
Net income	$ 45,126	$ 33,133	$ 25,237
Basic income per share
Continuing operations	$ 2.87	$ 2.12	$ 1.87
Discontinued operations			(0.04)
Basic income per share	2.87	2.12	1.83
Diluted income per share
Continuing operations	2.81	2.08	1.81
Discontinued operations			(0.04)
Diluted income per share	$ 2.81	$ 2.08	$ 1.77
Weighted average number of common shares and potential common shares outstanding:
Basic	15,737	15,596	13,816
Diluted	16,064	15,956	14,248