Net Property and Equipment - Schedule of Net Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment, Net [Abstract]
Proved crude oil and natural gas properties	$ 24,060,625	$ 21,362,199
Unproved crude oil and natural gas properties	291,564	365,413
Service properties, equipment and other	324,758	290,111
Total property and equipment	24,676,947	22,017,723
Accumulated depreciation, depletion and amortization	(10,807,147)	(9,083,934)
Net property and equipment	$ 13,869,800	$ 12,933,789