Derivative Activities - Effects of Derivatives on Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivative [Line Items]
Derivative Fair Value Income (Loss)	$ (162,798)	$ (34,791)	$ (75,890)	$ 88,048
Collars
Derivative [Line Items]
Derivative Fair Value Income (Loss)	0	(1,650)	0	6,765
Basis Swaps
Derivative [Line Items]
Derivative Fair Value Income (Loss)	(4,199)	8,959	3,075	(2,393)
Commodity | Swaps
Derivative [Line Items]
Derivative Fair Value Income (Loss)	(158,576)	(42,100)	(78,931)	83,676
Freight | Swaps
Derivative [Line Items]
Derivative Fair Value Income (Loss)	$ (23)	$ 0	$ (34)	$ 0