Organization and Basis of Presentation (Schedule of Cash Received and Allocated Losses from Subsidiaries, Noncontrolling Interest) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash received for the sale of noncontrolling interest to tax equity members	$ 239	$ 7	$ 402	$ 200
Cash received for the sale of noncontrolling interest to pro rata share members	0	0	0	415
Total Noncontrolling Interest Capital Contributions	239	7	402	615
Allocated losses to noncontrolling tax equity members utilizing the HLBV method	59	15	187	105
Allocated losses to noncontrolling members based on pro rata shares of ownership	11	4	21	5
Total Noncontrolling Interest Allocated Losses	$ 70	$ 19	$ 208	$ 110