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
3 Months Ended 12 Months Ended
Mar. 31, 2017
USD ($)
Customer
Mar. 31, 2016
USD ($)
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 $ 31.2    
Concentration risk, percentage 90.00%    
Successor [Member] | Accounts Receivable | Credit Concentration Risk      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Concentration risk, percentage 86.00%    
Accounts receivable, major customers $ 20.2    
Predecessor [Member] | Sales Revenue | Customer Concentration Risk      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Number of major customers | Customer   2  
Revenues, major customers   $ 26.5  
Concentration risk, percentage   88.00%  
Predecessor [Member] | Sales Revenue | Customer Concentration Risk | Major Customer 1      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers   $ 13.9  
Concentration risk, percentage   46.00%  
Predecessor [Member] | Sales Revenue | Customer Concentration Risk | Major Customer 2      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revenues, major customers   $ 12.6  
Concentration risk, percentage   42.00%