Operating Segments (Tables)

6 Months Ended

Jun. 30, 2016

Segment Reporting [Abstract]

Schedule of Information about Reportable Segments

						Project
	Products		Research			Consulting		Consolidated
Three Months Ended June 30, 2016
Research services revenues	$	55,023	$	—		$	—	$	55,023
Advisory services and events revenues		9,157		12,676			10,965		32,798
Total segment revenues		64,180		12,676			10,965		87,821
Segment expenses		12,544		12,822			7,022		32,388
Contribution margin (loss)		51,636		(146	)		3,943		55,433
Selling, marketing, administrative and other expenses									(43,740	)
Amortization of intangible assets									(210	)
Reorganization costs									(11	)
Other income (expense) and gains (losses) on investments									419
Income before income taxes								$	11,891

						Project
	Products		Research			Consulting		Consolidated
Three Months Ended June 30, 2015
Research services revenues	$	52,604	$	—		$	—	$	52,604
Advisory services and events revenues		8,255		11,323			10,629		30,207
Total segment revenues		60,859		11,323			10,629		82,811
Segment expenses		11,532		12,808			6,773		31,113
Contribution margin (loss)		49,327		(1,485	)		3,856		51,698
Selling, marketing, administrative and other expenses									(41,300	)
Amortization of intangible assets									(224	)
Reorganization costs									(81	)
Other income (expense) and gains (losses) on investments									(89	)
Income before income taxes								$	10,004

						Project
	Products		Research			Consulting		Consolidated
Six Months Ended June 30, 2016
Research services revenues	$	108,271	$	—		$	—	$	108,271
Advisory services and events revenues		11,858		23,262			21,831		56,951
Total segment revenues		120,129		23,262			21,831		165,222
Segment expenses		21,422		26,159			13,802		61,383
Contribution margin (loss)		98,707		(2,897	)		8,029		103,839
Selling, marketing, administrative and other expenses									(88,210	)
Amortization of intangible assets									(419	)
Reorganization costs									(1,026	)
Other income (expense) and gains (losses) on investments									91
Income before income taxes								$	14,275

						Project
	Products		Research			Consulting		Consolidated
Six Months Ended June 30, 2015
Research services revenues	$	104,462	$	—		$	—	$	104,462
Advisory services and events revenues		10,722		21,650			21,164		53,536
Total segment revenues		115,184		21,650			21,164		157,998
Segment expenses		19,881		25,756			13,733		59,370
Contribution margin (loss)		95,303		(4,106	)		7,431		98,628
Selling, marketing, administrative and other expenses									(85,300	)
Amortization of intangible assets									(445	)
Reorganization costs									(3,505	)
Other income (expense) and gains (losses) on investments									174
Income before income taxes								$	9,552