Derivative Financial Instruments - Summary of Notional Amounts and Estimated Fair Values of Oil and Gas Derivative Positions Outstanding (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	$ 21,686	$ 20,745
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Interest Receivable and Other Assets	Interest Receivable and Other Assets
Derivative liabilities, Estimated Fair Value	$ (19,558)	$ (19,683)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Liabilities	Other Liabilities
Not Designated as Hedging Instrument [Member] | Oil and Natural Gas Swaps and Options [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	$ 21,686	$ 20,745
Derivative liabilities, Estimated Fair Value	(19,558)	(19,683)
Not Designated as Hedging Instrument [Member] | Oil and Natural Gas Swaps and Options [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Notional Amount	4,041	2,698
Derivative liabilities, Notional Amount	(4,041)	(2,698)
Derivative assets, Estimated Fair Value	12,352	8,868
Derivative liabilities, Estimated Fair Value	(11,204)	(8,259)
Not Designated as Hedging Instrument [Member] | Oil and Natural Gas Swaps and Options [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Notional Amount	54,266	25,059
Derivative liabilities, Notional Amount	(54,266)	(25,059)
Derivative assets, Estimated Fair Value	9,334	11,877
Derivative liabilities, Estimated Fair Value	$ (8,354)	$ (11,424)