Consolidated Condensed Statements Of Income (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net revenue:
Service revenue	$ 382,873	$ 339,390	$ 1,115,237	$ 1,005,006
Reimbursed revenue	32,522	25,985	91,063	77,054
Total net revenue	415,395	365,375	1,206,300	1,082,060
Direct costs	223,507	189,979	651,720	564,948
Research and development expenses	2,069	470	6,081	15,253
Selling, general and administrative expenses	107,579	102,365	322,981	327,381
Depreciation and amortization	16,821	15,726	50,504	49,877
Total operating expenses	349,976	308,540	1,031,286	957,459
Operating income	65,419	56,835	175,014	124,601
(Loss) income from equity method investment	1,915	(4,562)	15,103	(8,351)
Gain (loss) on investments	(17,703)		(18,808)	2,541
Other income (expense), net	1,069	877	1,129	2,358
Income from continuing operations before provision for income taxes	50,700	53,150	172,438	121,149
Provision for income taxes	15,083	15,148	54,039	41,303
Income from continuing operations	35,617	38,002	118,399	79,846
Loss from discontinued operations, net of income taxes				(3,662)
Net income	35,617	38,002	118,399	76,184
Net (income) loss attributable to noncontrolling interests	(181)		1,157
Net income attributable to shareholders	$ 35,436	$ 38,002	$ 119,556	$ 76,184
Income per common share from continuing operations:
Basic	$ 0.31	$ 0.32	$ 1.04	$ 0.67
Diluted	$ 0.31	$ 0.32	$ 1.03	$ 0.67
Basic and diluted loss per common share from discontinued operations				$ (0.03)
Net income per common share
Basic	$ 0.31	$ 0.32	$ 1.04	$ 0.64
Diluted	$ 0.31	$ 0.32	$ 1.03	$ 0.64
Dividends declared per common share	$ 0.15	$ 0.15	$ 0.45	$ 0.45
Weighted-average number of common shares outstanding:
Basic	113,891	118,814	114,708	118,607
Dilutive effect of stock options and restricted stock	1,298	991	1,320	964
Diluted	115,189	119,805	116,028	119,571