Quarterly report pursuant to Section 13 or 15(d)

Accounts Receivable and Major Customers - Additional Information (Detail)

v3.7.0.1
Accounts Receivable and Major Customers - Additional Information (Detail)
$ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2017
USD ($)
Customer
Jun. 30, 2016
USD ($)
Customer
Dec. 31, 2016
USD ($)
Accounts Receivable | Credit Concentration Risk      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Concentration risk, percentage     81.00%
Accounts receivable, major customers     $ 16.7
Successor [Member] | Sales Revenue | Customer Concentration Risk      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Number of major customers | Customer 1    
Revenues, major customers $ 64.6    
Concentration risk, percentage 91.00%    
Successor [Member] | Accounts Receivable | Credit Concentration Risk      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Concentration risk, percentage 84.00%    
Accounts receivable, major customers $ 19.2    
Predecessor [Member] | Sales Revenue | Customer Concentration Risk      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Number of major customers | Customer   3  
Revenues, major customers   $ 62.2  
Concentration risk, percentage   93.00%  
Predecessor [Member] | Sales Revenue | Customer Concentration Risk | Major Customer 1      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers   $ 32.1  
Concentration risk, percentage   48.00%  
Predecessor [Member] | Sales Revenue | Customer Concentration Risk | Major Customer 2      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers   $ 16.2  
Concentration risk, percentage   24.00%  
Predecessor [Member] | Sales Revenue | Customer Concentration Risk | Major Customer 3      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers   $ 13.9  
Concentration risk, percentage   21.00%