Quarterly report pursuant to Section 13 or 15(d)

Cash Equivalents and Marketable Securities - Additional Information (Details)

v3.19.3
Cash Equivalents and Marketable Securities - Additional Information (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended
Dec. 31, 2009
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Dec. 31, 2018
Jan. 01, 2018
Cash and Cash Equivalents [Line Items]              
Cash and cash equivalents   $ 92,143 $ 54,225 $ 92,143 $ 54,225 $ 53,039  
Cash, cash equivalents, and short-term investments           31,813  
Percentage of outstanding shares owned at time of investment 16.60%            
Statutory resale restriction expiry period 4 months            
Proceeds from the sale of investment securities       62 0    
Equity securities, estimated fair value           588  
Accounting Standards Update 2016-01 [Member]              
Cash and Cash Equivalents [Line Items]              
Cumulative effect of change on equity or net assets             $ 500
Other Expense [Member]              
Cash and Cash Equivalents [Line Items]              
Gain (loss) on equity securities     $ (25)   $ (20)    
Common Shares of Co Two Solution [Member]              
Cash and Cash Equivalents [Line Items]              
Number of common shares fair value (in shares) 10,000,000            
Number of common shares sold (in shares)   1,300,000          
Proceeds from the sale of investment securities   $ 100          
Common Shares of Co Two Solution [Member] | Other Expense [Member]              
Cash and Cash Equivalents [Line Items]              
Gain (loss) on equity securities   (400)   (500)      
Money Market Funds [Member]              
Cash and Cash Equivalents [Line Items]              
Cash and cash equivalents   73,450   73,450   31,225  
Cash, cash equivalents, and short-term investments   73,500   73,500   31,200  
Cash [Member]              
Cash and Cash Equivalents [Line Items]              
Cash, cash equivalents, and short-term investments   $ 18,600   $ 18,600   $ 21,800