XML 123 R109.htm IDEA: XBRL DOCUMENT v3.8.0.1
Trade and Other Receivables - Movement in Provision for Impairment of Trade Receivables (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Disclosure of financial assets [Line Items]    
Write-off $ (2,000) $ (1,800)
Trade receivables [Member]    
Disclosure of financial assets [Line Items]    
Beginning balance 3,342 3,289
Charge for the year 610 348
Write-off (429) (91)
Unused amounts reversed (308) (69)
Currency translation adjustment 260 (135)
Reclassification (3)  
Ending balance 3,472 3,342
Trade receivables [Member] | Individually impaired [Member]    
Disclosure of financial assets [Line Items]    
Beginning balance 2,981 3,129
Charge for the year 438 106
Write-off (385) (85)
Unused amounts reversed (269) (21)
Currency translation adjustment 223 (132)
Reclassification (3) (16)
Ending balance 2,985 2,981
Trade receivables [Member] | Collectively impaired [Member]    
Disclosure of financial assets [Line Items]    
Beginning balance 361 160
Charge for the year 172 242
Write-off (44) (6)
Unused amounts reversed (39) (48)
Currency translation adjustment 37 (3)
Reclassification   16
Ending balance $ 487 $ 361