CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenue	$ 341,254	$ 302,780
Direct costs	215,949	188,826
Operating costs and expenses:
Indirect and selling expenses	96,519	89,659
Depreciation and amortization	4,762	4,469
Amortization of intangible assets	2,135	2,244
Total operating costs and expenses	103,416	96,372
Operating income	21,889	17,582
Interest expense	(2,453)	(1,666)
Other (expense) income	(412)	104
Income before income taxes	19,024	16,020
Provision for income taxes	3,706	3,603
Net income	$ 15,318	$ 12,417
Earnings per Share:
Basic	$ 0.81	$ 0.67
Diluted	$ 0.80	$ 0.65
Weighted-average Shares:
Basic	18,825	18,670
Diluted	19,263	19,158
Cash dividends declared per common share	$ 0.14	$ 0.14
Other comprehensive income, net of tax	$ 283	$ 1,609
Comprehensive income, net of tax	$ 15,601	$ 14,026