Risk Management and Hedging Activities - Schedule of Net Long or Short Positions Expected to be Realized (Detail)	3 Months Ended
	Mar. 31, 2020 MMBTU bbl	Mar. 31, 2019 MMBTU bbl
Crude Oil
Net (Short) Position, Volume [Abstract]
Net (Short) Position (Bbls), Year One | bbl	(1,410,000)	(1,191,000)
Net (Short) Position (Bbls), Year Two | bbl	(1,467,000)	(283,000)
Net (Short) Position (Bbls), Year Three | bbl	(107,000)	(100,000)
Net (Short) Position (Bbls), Year Four | bbl	0	0
Net Long (Short) Position (Bbls), Year Five | bbl	0
Natural Gas [Member]
Net Long (Short) Position, MMBtu [Abstract]
Net (Short) Long Position (MMBtu), Year One | MMBTU	(27,659,800)	(32,148,650)
Net (Short) Long Position (MMBtu), Year Two | MMBTU	(45,540,000)	(930,000)
Net Long Position (MMBtu), Year Three | MMBTU	(13,687,500)	0
Net Long Position (MMBtu), Year Four | MMBTU	0	0
Net Long Position (MMBtu), Year Five | MMBTU	0
Natural Gas Liquids
Net (Short) Position, Volume [Abstract]
Net (Short) Position (Bbls), Year One | bbl	(25,009,803)	(26,987,090)
Net (Short) Position (Bbls), Year Two | bbl	(7,294,133)	(14,388,830)
Net (Short) Position (Bbls), Year Three | bbl	(104,842)	(5,516,168)
Net (Short) Position (Bbls), Year Four | bbl	0	(175)
Net Long (Short) Position (Bbls), Year Five | bbl	0
Natural Gas Basis Swaps
Net Long (Short) Position, MMBtu [Abstract]
Net (Short) Long Position (MMBtu), Year One | MMBTU	8,190,000	2,102,500
Net (Short) Long Position (MMBtu), Year Two | MMBTU	4,325,000	3,660,000
Net Long Position (MMBtu), Year Three | MMBTU	8,212,500	(3,650,000)
Net Long Position (MMBtu), Year Four | MMBTU	7,300,000	0
Net Long Position (MMBtu), Year Five | MMBTU	2,140,000