Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:
Research services	$ 202,843	$ 203,091	$ 191,495
Advisory services and other	94,807	89,940	91,840
Total revenues	297,650	293,031	283,335
Operating expenses:
Cost of services and fulfillment	117,061	111,228	103,571
Selling and marketing	107,073	101,390	101,468
General and administrative	38,280	36,866	33,284
Depreciation	9,268	8,921	5,359
Amortization of intangible assets	2,230	2,445	2,562
Reorganization costs	1,905	1,421	375
Total operating expenses	275,817	262,271	246,619
Income from operations	21,833	30,760	36,716
Other income, net	592	1,300	630
Gains (losses) on investments, net	(2,433)	94	(399)
Income before income taxes	19,992	32,154	36,947
Income tax provision	6,968	5,858	14,956
Net income	$ 13,024	$ 26,296	$ 21,991
Basic income per common share	$ 0.62	$ 1.17	$ 0.97
Diluted income per common share	$ 0.61	$ 1.15	$ 0.95
Basic weighted average common shares outstanding	20,861	22,500	22,666
Diluted weighted average common shares outstanding	21,353	22,929	23,164