Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Total revenues	$ 128,183	$ 96,353	$ 228,832	$ 174,102
Operating expenses:
Selling and marketing	44,017	32,709	86,050	65,720
General and administrative	13,221	10,940	26,411	21,679
Depreciation	2,166	2,095	4,189	4,091
Amortization of intangible assets	5,099	182	11,309	368
Acquisition and integration costs	2,487	329	5,454	329
Total operating expenses	123,561	85,326	235,094	165,363
Income (loss) from operations	4,622	11,027	(6,262)	8,739
Interest expense	(2,085)		(4,437)
Other income (expense), net	(86)	271	(356)	153
Losses on investments, net	(8)	(20)	(44)	(45)
Income (loss) before income taxes	2,443	11,278	(11,099)	8,847
Income tax expense	888	3,490	662	2,792
Net income (loss)	$ 1,555	$ 7,788	$ (11,761)	$ 6,055
Basic income (loss) per common share	$ 0.08	$ 0.43	$ (0.64)	$ 0.34
Diluted income (loss) per common share	$ 0.08	$ 0.43	$ (0.64)	$ 0.33
Basic weighted average common shares outstanding	18,435	17,965	18,399	18,001
Diluted weighted average common shares outstanding	18,780	18,290	18,399	18,313
Cash dividends declared per common share		$ 0.20		$ 0.40
Research Services [Member]
Revenues:
Total revenues	$ 76,279	$ 58,300	$ 144,888	$ 110,000
Advisory Services and Events [Member]
Revenues:
Total revenues	51,904	38,053	83,944	64,102
Cost of Services and Fulfillment [Member]
Operating expenses:
Cost of services and fulfillment	$ 56,571	$ 39,071	$ 101,681	$ 73,176