XML 127 R113.htm IDEA: XBRL DOCUMENT v3.19.1
Trade and Other Receivables - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Trade And Other Receivables [Abstract]    
Loss allowance on trade receivables   $ 2,000
Fair values of collateral $ 1,200 1,181
Impairment loss $ 52 $ 0