Annual report pursuant to Section 13 and 15(d)

Investments - Narrative (Details)

v3.19.1
Investments - Narrative (Details) - Venture Capital Funds - USD ($)
$ in Millions
12 Months Ended
Nov. 21, 2013
Dec. 31, 2018
Investment [Line Items]    
Capital commitment $ 5.0 $ 1.8
Cash distribution   $ 0.3
Finjan Holdings    
Investment [Line Items]    
Percentage of limited partnership interest 10.00%