Earnings Per Share (Narrative) (Details) - Montage Resources Corporation - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Aug. 31, 2020	Nov. 13, 2020
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Offering price (in dollars per share)		$ 3.05
Public Stock Offering
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Underwritten public offering of common stock (in shares)	63,250,000
Offering price (in dollars per share)	$ 2.50
Net proceeds from public offering	$ 152