Accounts Receivable, Accounts Payable and Accrued Expenses - Accounts Receivable (Details) - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]    
Accrued oil and gas sales receivable $ 32,294 $ 11,596
Joint interest billings 16,989 2,942
Hedge settlements 126 194
Other 798 2
Accounts receivable, net $ 50,207 $ 14,734