Organization and Basis of Presentation (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Noncontrolling Interest [Line Items]
Other current liabilities	$ 1,994		$ 2,936
Charges related to reduction in physical workspace	175
Impairment of assets and other charges
Noncontrolling Interest [Line Items]
Charges related to reduction in physical workspace	131
Operation, maintenance and other
Noncontrolling Interest [Line Items]
Charges related to reduction in physical workspace	27
Depreciation and amortization
Noncontrolling Interest [Line Items]
Charges related to reduction in physical workspace	17
Forecast
Noncontrolling Interest [Line Items]
Charges related to reduction in physical workspace		$ 200
ACP
Noncontrolling Interest [Line Items]
Other current liabilities	$ 41		$ 936