Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v2.4.0.6
Fair Value Measurements (Details) (USD $)
Sep. 30, 2012
Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Available-for-sale Securities $ 90,000 $ 127,000
Carrying (Reported) Amount, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 60,529,000  
Marketable Securities, Fair Value Disclosure 4,904,000  
Estimate of Fair Value, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 60,529,000  
Marketable Securities, Fair Value Disclosure 4,904,000  
Fair Value, Inputs, Level 1 [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 60,529,000  
Marketable Securities, Fair Value Disclosure 4,904,000  
Money Market Funds [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 48,000  
Money Market Funds [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 48,000  
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 48,000  
Mutual Funds [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 42,000  
Mutual Funds [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 42,000  
Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 42,000  
US Treasury Securities [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 3,537,000  
US Treasury Securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 3,537,000  
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 3,537,000  
US Government Agencies Securities [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 1,277,000  
US Government Agencies Securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 1,277,000  
US Government Agencies Securities [Member] | Fair Value, Inputs, Level 1 [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Marketable Securities, Fair Value Disclosure 1,277,000  
Cash [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 18,698,000  
Cash [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 18,698,000  
Cash [Member] | Fair Value, Inputs, Level 1 [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 18,698,000  
Money Market Funds [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 41,831,000  
Money Market Funds [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 41,831,000  
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure $ 41,831,000