Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Total revenues	$ 128,670	$ 113,541	$ 242,451	$ 219,886
Operating expenses:
Selling and marketing	42,556	39,117	81,835	79,390
General and administrative	14,334	11,456	27,512	23,461
Depreciation	2,255	2,448	4,545	4,854
Amortization of intangible assets	3,968	4,713	7,871	9,425
Integration costs	216	612	334	3,487
Total operating expenses	115,587	102,310	221,832	207,934
Income from operations	(13,083)	11,231	20,619	11,952
Interest expense	(1,066)	(1,307)	(2,195)	(2,845)
Other income (expense), net	(201)	(201)	(671)	109
Gain on investments, net	0	2,352	0	2,365
Income before income taxes	11,816	12,075	17,753	11,581
Income tax expense	3,473	238	5,454	257
Net income	$ 8,343	$ 11,837	$ 12,299	$ 11,324
Basic income per common share	$ (0.44)	$ 0.63	$ 0.64	$ 0.60
Diluted income per common share	$ (0.43)	$ 0.63	$ 0.64	$ 0.60
Basic weighted average common shares outstanding	19,126	18,759	19,094	18,732
Diluted weighted average common shares outstanding	19,377	18,831	19,332	18,828
Research [Member]
Revenues:
Total revenues	$ 81,002	$ 75,034	$ 155,970	$ 149,301
Consulting [Member]
Revenues:
Total revenues	40,960	33,475	79,510	65,463
Events [Member]
Revenues:
Total revenues	6,708	5,032	6,971	5,122
Cost of Services and Fulfillment [Member]
Operating expenses:
Cost of services and fulfillment	$ 52,258	$ 43,964	$ 99,735	$ 87,317