Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Total revenues	$ 970,444	$ 963,565
Costs and expenses:
Cost of services and product development	346,645	357,209
Selling, general and administrative	518,770	487,745
Depreciation	19,775	16,410
Amortization of intangibles	33,683	51,646
Acquisition and integration charges	2,772	59,266
Total costs and expenses	921,645	972,276
Operating income (loss)	48,799	(8,711)
Interest expense, net	(24,847)	(35,059)
Loss from divested operations	(2,075)	0
Other (expense) income, net	(824)	899
Income (loss) before income taxes	21,053	(42,871)
Provision (benefit) for income taxes	258	(23,284)
Net income (loss)	$ 20,795	$ (19,587)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.23	$ (0.22)
Diluted (in dollars per share)	$ 0.23	$ (0.22)
Weighted average shares outstanding:
Basic (in shares)	89,882	91,005
Diluted (in shares)	91,004	91,005
Research
Revenues:
Total revenues	$ 825,374	$ 763,924
Conferences
Revenues:
Total revenues	51,932	46,087
Consulting
Revenues:
Total revenues	93,138	82,896
Other
Revenues:
Total revenues	$ 0	$ 70,658