Property, Plant and Equipment - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Impairment charge	$ 2,578,000	$ 0	$ 4,828,575,000	$ 653,000
Proved Oil And Gas Properties
Property, Plant and Equipment [Line Items]
Impairment	0	0	4,400,000,000	0
Proved Oil And Gas Properties | Williston Basin
Property, Plant and Equipment [Line Items]
Impairment			3,800,000,000
Proved Oil And Gas Properties | Delaware Basin
Property, Plant and Equipment [Line Items]
Impairment			637,300,000
Unproved Oil And Gas Properties
Property, Plant and Equipment [Line Items]
Impairment charge	900,000	0	293,000,000.0	700,000
Other Property, Plant and Equipment | Williston Basin and Delaware Basin
Property, Plant and Equipment [Line Items]
Impairment charge			108,300,000
Midstream Assets
Property, Plant and Equipment [Line Items]
Impairment charge	$ 1,100,000	$ 0	$ 1,600,000	$ 0