Annual report pursuant to Section 13 and 15(d)

Intangible Assets - Additional Information (Detail)

v3.8.0.1
Intangible Assets - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Finite Lived Intangible Assets [Line Items]        
Intangible amortization expense   $ 236 $ 234 $ 234
Impairment losses, intangible assets   9,100    
Impairment losses, goodwill $ 5,716      
Goodwill   1,222 6,938  
Permits [Member]        
Finite Lived Intangible Assets [Line Items]        
Impairment losses, intangible assets 8,600 8,600    
Tradename [Member]        
Finite Lived Intangible Assets [Line Items]        
Impairment losses, intangible assets $ 500 500    
Customer Relationships [Member]        
Finite Lived Intangible Assets [Line Items]        
Intangible amortization expense   180 $ 180 $ 180
Future amortization expenses, 2019   180    
Future amortization expenses, 2020   180    
Future amortization expenses, 2021   180    
Future amortization expenses, 2022   180    
Future amortization expenses, 2023   $ 180