Annual report pursuant to Section 13 and 15(d)

Foreign Currency Translation - Additional Information (Detail)

v3.8.0.1
Foreign Currency Translation - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Foreign Currency Translation [Line Items]    
Accumulated other comprehensive income (loss) $ 253,282 $ 247,013
Cumulative foreign currency adjustments $ 253,565 $ 247,046
Cumulative inflation rate 100.00%  
Cumulative inflation period 3 years  
Reclassification of cumulative foreign currency translation adjustments $ (1,551)  
Canada    
Foreign Currency Translation [Line Items]    
Reclassification of cumulative foreign currency translation adjustments $ 1,551