Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment	$ 8,048,936	$ 8,089,473
Less accumulated depreciation, depletion and impairment	(5,421,024)	(5,328,432)
Property and equipment, net	2,627,912	2,761,041
Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	7,605,879	7,647,451
Oil and natural gas properties
Property Plant And Equipment [Line Items]
Total property and equipment	225,176	222,738
Buildings
Property Plant And Equipment [Line Items]
Total property and equipment	192,282	193,503
Land
Property Plant And Equipment [Line Items]
Total property and equipment	$ 25,599	$ 25,781