Earnings per Share (Weighted Average Shares Outstanding) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	11 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 13, 2019	Dec. 31, 2020	Dec. 31, 2018
Earnings Per Share [Abstract]
Weighted Average Number of Shares Outstanding, Basic and Diluted	70	1,004	70	997
Earnings Per Share, Basic and Diluted	$ (0.37)	$ 3.65	$ (27.44)	$ (2.82)
Net Income (Loss) Attributable to Weatherford	$ (26)	$ 3,661	$ (1,921)	$ (2,811)