Organization and Basis of Presentation (Schedule of Cash Received and Allocated Losses from Subsidiaries, Noncontrolling Interest) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash received for the sale of noncontrolling interest to tax equity members	$ 15	$ 60	$ 318	$ 163
Allocated losses to noncontrolling tax equity members utilizing the HLBV method	55	79	98	128
Allocated losses to noncontrolling members based on pro rata shares of ownership	12	11	20	10
Total Noncontrolling Interest Allocated Losses	$ 67	$ 90	$ 118	$ 138