Restructuring Charges (Restructuring Charges) (Details) - USD ($) $ in Millions	1 Months Ended	11 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 13, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 12, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 0	$ 189	$ 0	$ 206
Corporate and Other
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	0	59	0	59
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs	0	53	0	132
Severance and Other Restructuring Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	66	66	17	53	$ 66	$ 59
Impaired Assets to be Disposed of by Method Other than Sale, Asset Name [Domain]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs	0	13	0	40
Facility Closing
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs	0	99	0	10
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs	0	24	0	15
Asset Retirement Obligation Costs
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs	$ 0	$ 0	$ 0	$ 9