Derivative Activities - Effects of Derivatives on Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative [Line Items]
Derivative Fair Value (Loss) Income	$ (6,303)	$ 195,245	$ 226,872	$ 133,514
Swaptions
Derivative [Line Items]
Derivative Fair Value (Loss) Income	(2,019)	32,383	(1,353)	29,092
Collars
Derivative [Line Items]
Derivative Fair Value (Loss) Income	2,557	578	2,557	(3,946)
Three Way Collars
Derivative [Line Items]
Derivative Fair Value (Loss) Income	(6,200)		(17,562)	0
Calls
Derivative [Line Items]
Derivative Fair Value (Loss) Income	(33)		242	0
Basis Swaps
Derivative [Line Items]
Derivative Fair Value (Loss) Income	(5,180)	938	16,163	4,353
Commodity | Swaps
Derivative [Line Items]
Derivative Fair Value (Loss) Income	5,484	159,128	233,838	101,710
Freight | Swaps
Derivative [Line Items]
Derivative Fair Value (Loss) Income	$ (912)	$ 2,218	$ (7,013)	$ 2,305