v2.4.0.6
Goodwill and Intangible Assets (Schedule of Acquired Intangible Assets) (Detail) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Goodwill [Line Items]    
Gross Carrying Amount $ 63,029 $ 68,684
Accumulated Amortization (20,302) (15,570)
Net Carrying Amount 42,727 53,114
Acquired Methodologies/Technology [Member]
   
Goodwill [Line Items]    
Gross Carrying Amount 8,360 11,244
Accumulated Amortization (3,804) (3,307)
Net Carrying Amount 4,556 7,937
Customer Relationships [Member]
   
Goodwill [Line Items]    
Gross Carrying Amount 35,347 38,157
Accumulated Amortization (9,868) (7,698)
Net Carrying Amount 25,479 30,459
Panel [Member]
   
Goodwill [Line Items]    
Gross Carrying Amount 1,639 1,615
Accumulated Amortization (1,015) (826)
Net Carrying Amount 624 789
Intellectual Property [Member]
   
Goodwill [Line Items]    
Gross Carrying Amount 13,571 13,561
Accumulated Amortization (2,074) (918)
Net Carrying Amount 11,497 12,643
Trade Names [Member]
   
Goodwill [Line Items]    
Gross Carrying Amount 4,112 4,107
Accumulated Amortization (3,541) (2,821)
Net Carrying Amount $ 571 $ 1,286