Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Measurements [Line Items]
Operating cost escalation assumption used in impairment assessment	3.00%
Discount factor utilized as standardized measure for future net cash flows	10.00%
Impairments of proved properties	$ 138,878	$ 324,302	$ 51,805
Estimated fair value of proved properties	$ 59,900
Minimum [Member]
Fair Value Measurements [Line Items]
Productive life of field (in years)	0 years
Maximum [Member]
Fair Value Measurements [Line Items]
Productive life of field (in years)	34 years
Forward Commodity Prices [Member]
Fair Value Measurements [Line Items]
Forward commodity price escalation assumption used in impairment assessment	3.00%