XML 76 R39.htm IDEA: XBRL DOCUMENT v3.10.0.1
Summary of Significant Accounting Policies - Summary of Effect of Adopting ASC 606 In Consolidated Statement of Income (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Revenues:                      
Total revenues $ 98,583 $ 84,890 $ 96,353 $ 77,749 $ 90,377 $ 80,369 $ 89,733 $ 77,194 $ 357,575 $ 337,673 $ 326,095
Operating expenses:                      
Selling and marketing                 131,824 123,917 116,898
Total operating expenses                 335,150 310,124 295,321
Income from operations 8,744 4,942 11,027 (2,288) 7,451 6,749 10,213 3,136 22,425 27,549 30,774
Income before income taxes                 23,525 27,371 30,709
Income tax provision                 8,145 12,231 13,058
Net income $ 5,375 $ 3,950 $ 7,788 $ (1,733) $ 2,093 $ 3,953 $ 6,064 $ 3,030 $ 15,380 $ 15,140 $ 17,651
Basic income per common share $ 0.29 $ 0.22 $ 0.43 $ (0.10) $ 0.12 $ 0.22 $ 0.34 $ 0.17 $ 0.85 $ 0.84 $ 0.98
Diluted income per common share $ 0.29 $ 0.21 $ 0.43 $ (0.10) $ 0.11 $ 0.22 $ 0.34 $ 0.16 $ 0.84 $ 0.83 $ 0.97
ASC 606 [Member] | Amounts as if Previous Guidance in Effect [Member]                      
Revenues:                      
Total revenues                 $ 355,931    
Operating expenses:                      
Selling and marketing                 131,907    
Total operating expenses                 335,397    
Income from operations                 20,534    
Income before income taxes                 21,634    
Income tax provision                 7,652    
Net income                 $ 13,982    
Basic income per common share                 $ 0.77    
Diluted income per common share                 $ 0.76    
Research Services [Member]                      
Revenues:                      
Total revenues                 $ 228,399 $ 216,471 $ 215,216
Research Services [Member] | ASC 606 [Member] | Amounts as if Previous Guidance in Effect [Member]                      
Revenues:                      
Total revenues                 227,059    
Advisory Services and Events [Member]                      
Revenues:                      
Total revenues                 129,176 121,202 110,879
Advisory Services and Events [Member] | ASC 606 [Member] | Amounts as if Previous Guidance in Effect [Member]                      
Revenues:                      
Total revenues                 128,872    
Cost of Services and Fulfillment [Member]                      
Operating expenses:                      
Cost of services and fulfillment                 146,502 $ 136,872 $ 128,175
Cost of Services and Fulfillment [Member] | ASC 606 [Member] | Amounts as if Previous Guidance in Effect [Member]                      
Operating expenses:                      
Cost of services and fulfillment                 $ 146,666