XML 20 R6.htm IDEA: XBRL DOCUMENT v3.10.0.1
Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]      
Unrealized (losses) gains on investments, tax $ (1,432) $ (505) $ 19