Organization and Summary of Significant Accounting Policies - Summary Of Changes In Future Abandonment Liabilities (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations at January 1		$ 141,360	$ 114,406	$ 96,178
Accretion expense		8,443	6,985	5,886
Revisions	[1]	(1,762)	13,075	7,801
Plus: Additions for new assets		8,392	9,070	6,884
Less: Plugging costs and sold assets		(2,760)	(2,176)	(2,343)
Total asset retirement obligations at December 31		$ 141,360	$ 114,406	$ 96,178	$ 153,673	$ 141,360	$ 114,406
Less: Current portion of asset retirement obligations at December 31	[2]				1,899	4,374	2,612
Non-current portion of asset retirement obligations at December 31					$ 151,774	$ 136,986	$ 111,794

[1] Revisions primarily represent changes in the present value of liabilities resulting from changes in estimated costs and economic lives of producing properties.

[2] Balance is included in the caption “Accrued liabilities and other” in the consolidated balance sheets.