Derivative Activities - Effects of Derivatives on Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative [Line Items]
Derivative Fair Value (Loss) Income	$ (57,879)	$ 233,175
Contingent Consideration
Derivative [Line Items]
Derivative Fair Value (Loss) Income	3,930	0
Swaptions
Derivative [Line Items]
Derivative Fair Value (Loss) Income	2,657	666
Collars
Derivative [Line Items]
Derivative Fair Value (Loss) Income	(13,288)	0
Three Way Collars
Derivative [Line Items]
Derivative Fair Value (Loss) Income	873	(11,362)
Calls
Derivative [Line Items]
Derivative Fair Value (Loss) Income	(775)	275
Basis Swaps
Derivative [Line Items]
Derivative Fair Value (Loss) Income	2,155	21,343
Commodity | Swap
Derivative [Line Items]
Derivative Fair Value (Loss) Income	(52,764)	228,354
Freight | Swap
Derivative [Line Items]
Derivative Fair Value (Loss) Income	$ (667)	$ (6,101)