Summary of Significant Accounting Policies - Summary of Lease Cost Recognized (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Operations And Summary Of Significant Accounting Policies [Line Items]
Operating lease cost	$ 9,142
General and Administrative Expense
Operations And Summary Of Significant Accounting Policies [Line Items]
Operating lease cost	411
Lease Operating Expense
Operations And Summary Of Significant Accounting Policies [Line Items]
Operating lease cost	91
Short-term Drilling Rig Costs Included in Proved Oil and Gas Properties
Operations And Summary Of Significant Accounting Policies [Line Items]
Operating lease cost	$ 8,640