XML 35 R25.htm IDEA: XBRL DOCUMENT v3.8.0.1
Marketable Securities (Narrative) (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Apr. 01, 2017
Net Investment Income [Line Items]    
Unrealized loss on equity securities $ 365  
Investment income   $ 1,100
Equity Securities [Member]    
Net Investment Income [Line Items]    
Unrealized loss on equity securities $ 780