Summary of Significant Accounting Policies - Summary of Lease Cost Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Operations And Summary Of Significant Accounting Policies [Line Items]
Operating lease cost	$ 19,814	$ 41,012
General and Administrative Expense
Operations And Summary Of Significant Accounting Policies [Line Items]
Operating lease cost	411	1,234
Lease Operating Expense
Operations And Summary Of Significant Accounting Policies [Line Items]
Operating lease cost	99	291
Short-term Drilling Rig Costs Included in Proved Oil and Gas Properties
Operations And Summary Of Significant Accounting Policies [Line Items]
Operating lease cost	$ 19,304	$ 39,487