XML 113 R60.htm IDEA: XBRL DOCUMENT v3.20.1
Defined Contribution Plan And Group Retirement Savings Plan - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Defined contribution plan expenses $ 125 $ 133 $ 138
Foreign Plan [Member]      
Defined contribution plan expenses $ 11 $ 9 $ 16