Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Consolidated Statements of Comprehensive Income [Abstract]
Gross Revenue	$ 237,864	$ 218,691	$ 705,154	$ 626,828
Direct Costs	148,267	137,343	436,316	389,086
Operating costs and expenses:
Indirect and selling expenses	66,356	60,336	199,613	177,483
Depreciation and amortization	2,886	2,544	7,501	8,083
Amortization of intangible assets	3,480	2,369	10,530	7,105
Total operating costs and expenses	72,722	65,249	217,644	192,671
Operating income	16,875	16,099	51,194	45,071
Interest expense	(804)	(539)	(2,722)	(1,732)
Other income (expense)	(116)	(5)	(379)	35
Income before income taxes	15,955	15,555	48,093	43,374
Provision for income taxes	6,382	6,221	19,237	17,351
Net income	9,573	9,334	28,856	26,023
Earnings per Share:
Basic	$ 0.49	$ 0.47	$ 1.46	$ 1.32
Diluted	$ 0.48	$ 0.47	$ 1.44	$ 1.31
Weighted-average Shares:
Basic	19,610	19,728	19,717	19,666
Diluted	19,770	19,860	20,004	19,888
Other comprehensive income:
Foreign currency translation adjustments	84	(211)	(535)	(11)
Comprehensive income	$ 9,657	$ 9,123	$ 28,321	$ 26,012