Consolidated Statements of Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements of Comprehensive Income [Abstract]
Gross Revenue	$ 239,649	$ 213,395	$ 467,290	$ 408,137
Direct Costs	147,861	133,522	288,049	251,743
Operating costs and expenses:
Indirect and selling expenses	67,404	59,239	133,257	117,147
Depreciation and amortization	2,800	2,778	4,615	5,539
Amortization of intangible assets	3,519	2,321	7,050	4,736
Total operating costs and expenses	73,723	64,338	144,922	127,422
Operating income	18,065	15,535	34,319	28,972
Interest expense	(611)	(564)	(1,918)	(1,193)
Other income (expense)	(212)	(29)	(263)	40
Income before income taxes	17,242	14,942	32,138	27,819
Provision for income taxes	6,896	5,979	12,855	11,130
Net income	10,346	8,963	19,283	16,689
Earnings per Share:
Basic	$ 0.52	$ 0.46	$ 0.98	$ 0.85
Diluted	$ 0.52	$ 0.45	$ 0.96	$ 0.84
Weighted-average Shares:
Basic	19,774	19,688	19,771	19,634
Diluted	19,971	19,847	20,061	19,849
Other comprehensive income:
Foreign currency translation adjustments	(230)	44	(619)	200
Comprehensive income	$ 10,116	$ 9,007	$ 18,664	$ 16,889