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Summary of Significant Accounting Policies - Summary of Other Current Assets (Detail) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Schedule Of Other Current Assets [Line Items]    
Other Current Assets $ 1,824 $ 1,993
Pipe and oil field equipment inventory    
Schedule Of Other Current Assets [Line Items]    
Other Current Assets 1,183 1,198
Other    
Schedule Of Other Current Assets [Line Items]    
Other Current Assets $ 641 $ 795