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Crude Oil and Natural Gas Property Information - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Oil and Gas Exploration and Production Industries Disclosures [Abstract]      
Development costs included in asset retirement costs $ (9.6) $ 22.8 $ 20.3