CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenue	$ 353,987	$ 366,717	$ 712,225	$ 707,971
Direct costs	223,407	235,053	454,023	451,002
Operating costs and expenses:
Indirect and selling expenses	99,255	101,450	202,526	197,969
Depreciation and amortization	5,064	5,595	10,243	10,357
Amortization of intangible assets	3,479	2,077	6,332	4,212
Total operating costs and expenses	107,798	109,122	219,101	212,538
Operating income	22,782	22,542	39,101	44,431
Interest expense	(3,908)	(2,934)	(7,433)	(5,387)
Other income (loss)	349	186	539	(226)
Income before income taxes	19,223	19,794	32,207	38,818
Provision for income taxes	5,567	5,183	7,939	8,889
Net income	$ 13,656	$ 14,611	$ 24,268	$ 29,929
Earnings per Share:
Basic	$ 0.73	$ 0.78	$ 1.29	$ 1.59
Diluted	$ 0.72	$ 0.76	$ 1.27	$ 1.56
Weighted-average Shares:
Basic	18,829	18,805	18,835	18,815
Diluted	19,020	19,133	19,120	19,213
Cash dividends declared per common share	$ 0.14	$ 0.14	$ 0.28	$ 0.28
Other comprehensive loss, net of tax	$ (164)	$ (2,853)	$ (11,287)	$ (2,570)
Comprehensive income, net of tax	$ 13,492	$ 11,758	$ 12,981	$ 27,359