Summary of Significant Accounting Policies - Summary of Accounts Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts	$ (106)	$ (106)
Accounts receivable	57,473	72,943
Accrued Oil, Gas, and NGL Sales
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable gross	45,626	44,860
Due from Joint Interest Owners
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable gross	10,543	27,435
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable gross	$ 1,410	$ 754