Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (Detail)

v3.19.2
Summary of Significant Accounting Policies (Detail)
$ in Thousands
 3 Months Ended 6 Months Ended
Apr. 01, 2019
Mar. 31, 2019
USD ($)
Mar. 30, 2019
Jun. 30, 2019
USD ($)
country
Mar. 31, 2019
USD ($)
Jun. 30, 2018
USD ($)
Jun. 30, 2019
USD ($)
country
Jun. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Revenue, Major Customer [Line Items]                    
Number of countries in which entity has operated since inception | country       60     60      
Percentage accounted for under the equity method       50.00%     50.00%      
Cash and cash equivalents       $ 139,099     $ 139,099   $ 48,602  
Restricted cash       2,024     2,024   10,389  
Cash, cash equivalents and restricted cash at end of period   $ 149,285   141,123 $ 149,285 $ 114,459 141,123 $ 114,459 58,991 $ 141,549
Revenues       156,031 157,397 $ 118,603   228,278    
Deposits in domestic banks in excess of federally insured limits       102,283     102,283   27,520  
Uninsured deposits in foreign banks       41,293     $ 41,293   32,907  
Predecessor and Successor Successor Predecessor Successor              
Reimbursable revenue                    
Revenue, Major Customer [Line Items]                    
Revenues       18,465 28,541     27,036    
Exxon Neftegas Limited | Reimbursable revenue                    
Revenue, Major Customer [Line Items]                    
Revenues       $ 16,900 $ 26,300     $ 22,600    
Customer Concentration Risk | Sales Revenue, Net | Exxon Neftegas Limited                    
Revenue, Major Customer [Line Items]                    
Percentage of revenue from major customer       26.90% 31.20%     26.30%    
Customer Concentration Risk | Sales Revenue, Net | Exxon Neftegas Limited | Reimbursable revenue                    
Revenue, Major Customer [Line Items]                    
Percentage of revenue from major customer       18.30% 17.70%          
Customer Concentration Risk | Sales Revenue, Net Of Reimbursable Revenues | Exxon Neftegas Limited | Reimbursable revenue                    
Revenue, Major Customer [Line Items]                    
Percentage of revenue from major customer               18.60%    
Minimum                    
Revenue, Major Customer [Line Items]                    
Estimated Useful Life (Years)             3 years      
Maximum                    
Revenue, Major Customer [Line Items]                    
Estimated Useful Life (Years)             6 years      
Compensating Balances                    
Revenue, Major Customer [Line Items]                    
Restricted cash                 600  
Collateral on Letters of Credit                    
Revenue, Major Customer [Line Items]                    
Restricted cash                 $ 9,800