v2.4.0.6
Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)
 12 Months Ended
Dec. 31, 2011
years
Dec. 31, 2010
Dec. 31, 2009
Summary Of Significant Accounting policies [Line Items]      
Percentage of holdings for consolidation 50.00%    
Available-for-sale Securities, gross realized gains $ 200,000    
Interest income on investments 100,000 300,000 600,000
Property and equipment, estimated useful life, minimum (in years) 3    
Property and equipment, estimated useful life, maximum (in years) 5    
Foreign currency transaction losses 400,000 300,000 100,000
Revenue recognized under old revenue recognition guidance 6,200,000    
Expense incurred under old revenue recognition guidance 1,400,000    
Revenue recognized under new revenue recognition guidance 2,400,000    
Expense incurred under new revenue recognition guidance 1,400,000    
Deferred revenue under the amended guidance 900,000    
Percentage of revenue accounted for customer 10.00% 11.00% 12.00%
Deferred cost of revenue under the amended guidance 300,000    
Percentage of revenue accounted for account receivables 10.00% 10.00%  
Advertising expense $ 100,000 $ 200,000 $ 200,000
Dilutive effect of stock options and restricted stock units 627,147 802,665 81,629
Minimum [Member]
      
Summary Of Significant Accounting policies [Line Items]      
Revenue recognition period 3    
Maximum [Member]
      
Summary Of Significant Accounting policies [Line Items]      
Revenue recognition period 24    
Service Arrangements [Member] | Minimum [Member]
      
Summary Of Significant Accounting policies [Line Items]      
Revenue recognition period 2    
Service Arrangements [Member] | Maximum [Member]
      
Summary Of Significant Accounting policies [Line Items]      
Revenue recognition period 1