Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Total revenues	$ 537,787	$ 494,315	$ 448,984
Operating expenses:
Selling and marketing	181,940	170,949	166,200
General and administrative	67,655	58,056	50,369
Depreciation	9,269	9,390	9,879
Amortization of intangible assets	13,161	15,129	19,683
Integration costs	0	334	5,779
Restructuring costs	9,335	0	0
Total operating expenses	505,133	455,673	432,809
Income from operations	32,654	38,642	(16,175)
Interest expense	(2,461)	(4,222)	(5,340)
Other income (expense), net	222	(1,229)	(374)
Gains on investments, net	309	0	2,472
Income before income taxes	30,724	33,191	12,933
Income tax expense	8,918	8,347	2,943
Net income	$ 21,806	$ 24,844	$ 9,990
Basic income per common share	$ 1.15	$ 1.30	$ (0.53)
Diluted income per common share	$ 1.14	$ 1.28	$ 0.53
Basic weighted average common shares outstanding	18,967	19,110	18,827
Diluted weighted average common shares outstanding	19,172	19,357	18,935
Research [Member]
Revenues:
Total revenues	$ 354,453	$ 325,340	$ 301,544
Consulting [Member]
Revenues:
Total revenues	152,587	156,114	137,303
Events [Member]
Revenues:
Total revenues	30,747	12,861	10,137
Cost of Services and Fulfillment [Member]
Operating expenses:
Cost of services and fulfillment	$ 223,773	$ 201,815	$ 180,899