UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 345,558	$ 326,584	$ 1,011,157	$ 973,560
Direct costs	242,747	230,539	714,144	684,786
Gross profit	102,811	96,045	297,013	288,774
Selling, general and administrative expenses	79,223	74,398	237,053	230,096
Depreciation and amortization	1,427	1,700	4,619	5,143
Income from operations	22,161	19,947	55,341	53,535
Other expense, net	880	1,052	2,206	3,654
Income from continuing operations, before income taxes	21,281	18,895	53,135	49,881
Income tax expense	5,374	4,739	13,178	12,595
Income from continuing operations	15,907	14,156	39,957	37,286
(Loss) income from discontinued operations, net of tax	(967)	2,021	76,697	4,338
Net income	14,940	16,177	116,654	41,624
Other comprehensive (loss) income:
Change in fair value of interest rate swap, net of tax	(113)		(871)
Change in fair value of interest swap, net of tax		110		807
Comprehensive income	$ 14,827	$ 16,287	$ 115,783	$ 42,431
Earnings per share – basic:
Continuing operations (in dollars per share)	$ 0.70	$ 0.57	$ 1.68	$ 1.50
Discontinued operations (in dollars per share)	(0.04)	0.08	3.24	0.18
Earnings per share - basic (in dollars per share)	0.66	0.65	4.92	1.68
Earnings per share – diluted:
Continuing operations (in dollars per share)	0.68	0.56	1.65	1.48
Discontinued operations (in dollars per share)	(0.04)	0.08	3.16	0.17
Earnings per share – diluted (in dollars per share)	$ 0.64	$ 0.64	$ 4.81	$ 1.65
Weighted average shares outstanding – basic (in shares)	22,770	24,730	23,723	24,746
Weighted average shares outstanding – diluted (in shares)	23,342	25,366	24,278	25,252