CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CONSOLIDATED STATEMENTS OF INCOME
Net revenues	$ 2,180,621	$ 2,095,938	$ 1,925,630
Reimbursable out-of-pocket expenses	185,138	140,508	112,843
Total revenues	2,365,759	2,236,446	2,038,473
Costs and expenses:
Cost of revenue (excluding depreciation and amortization)	1,570,223	1,467,051	1,348,498
Reimbursable out-of-pocket expenses	185,138	140,508	112,843
Selling, general and administrative (excluding depreciation and amortization)	358,854	343,044	307,386
Depreciation and amortization	117,708	105,214	103,024
Impairment charges	17,959	0	119,229
Total costs and expenses	2,249,882	2,055,817	1,990,980
Income from operations	115,877	180,629	47,493
Other expense, net:
Interest income	(2,011)	(1,874)	(1,479)
Interest expense	5,517	3,853	1,531
Foreign exchange transaction loss, net	1,474	1,248	3,649
Impairment of equity investment	7,373	12,119	0
Gain on sale of investment	(1,459)	0	0
Loss on sale of business	169	0	0
Other expense, net	11,063	15,346	3,701
Income before taxes and equity investee earnings	104,814	165,283	43,792
Taxes on income	10,099	33,574	(23,655)
Equity investee earnings	17	480	807
Net income	$ 94,732	$ 132,189	$ 68,254
Basic earnings per share	$ 1.73	$ 2.22	$ 1.08
Weighted average shares outstanding-basic	54,844,641	59,629,788	63,043,561
Diluted earnings per share	$ 1.68	$ 2.16	$ 1.06
Weighted average shares outstanding-diluted	56,290,010	61,091,354	64,472,326