Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Total property and equipment	$ 8,756,821	$ 8,803,668
Less accumulated depreciation, depletion and impairment	(4,987,563)	(4,801,119)
Property and equipment, net	3,769,258	4,002,549
Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	8,321,611	8,370,933
Oil and natural gas properties
Property Plant And Equipment [Line Items]
Total property and equipment	220,634	219,855
Buildings
Property Plant And Equipment [Line Items]
Total property and equipment	187,958	186,736
Land
Property Plant And Equipment [Line Items]
Total property and equipment	$ 26,618	$ 26,144