UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 365,424	$ 345,558	$ 1,043,652	$ 1,011,157
Direct costs	261,546	242,747	747,889	714,144
Gross profit	103,878	102,811	295,763	297,013
Selling, general and administrative expenses	75,852	79,223	235,614	237,053
Depreciation and amortization	1,308	1,427	4,081	4,619
Income from operations	26,718	22,161	56,068	55,341
Other expense, net	938	880	3,746	2,206
Income from continuing operations, before income taxes	25,780	21,281	52,322	53,135
Income tax expense	7,017	5,374	14,568	13,178
Income from continuing operations	18,763	15,907	37,754	39,957
Income from discontinued operations, net of tax	0	(967)	0	76,697
Net income	18,763	14,940	37,754	116,654
Other comprehensive loss:
Change in fair value of interest rate swaps, net of tax	118	(113)	(1,473)	(871)
Comprehensive income	$ 18,881	$ 14,827	$ 36,281	$ 115,783
Earnings per share – basic:
Continuing operations (in dollars per share)	$ 0.90	$ 0.70	$ 1.79	$ 1.68
Discontinued operations (in dollars per share)	0	(0.04)	0	3.24
Earnings per share - basic (in dollars per share)	0.90	0.66	1.79	4.92
Earnings per share – diluted:
Continuing operations (in dollars per share)	0.89	0.68	1.77	1.65
Discontinued operations (in dollars per share)	0	(0.04)	0	3.16
Earnings per share – diluted (in dollars per share)	$ 0.89	$ 0.64	$ 1.77	$ 4.81
Weighted average shares outstanding – basic (in shares)	20,782	22,770	21,041	23,723
Weighted average shares outstanding – diluted (in shares)	21,180	23,342	21,369	24,278