Investments Accounted for Using the Equity Method and Variable Interest Entities, or VIEs (Details) $ in Millions	3 Months Ended	6 Months Ended		9 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) project MW	Jun. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Investments Accounted for by the Equity Method
Equity investments in affiliates		$ 383			$ 412
Generation capacity (in MW) | MW		23,000
Loss on deconsolidation			$ 22
Current assets		$ 3			3
Net property, plant and equipment		74			76
Other long-term assets		29			28
Total assets		106			107
Current liabilities		1			2
Long-term debt		28			29
Other long-term liabilities		8			7
Total liabilities		37			38
Redeemable noncontrolling interest		19			19
Net assets less noncontrolling interests		50			$ 50
Agua Caliente
Investments Accounted for by the Equity Method
Equity investments in affiliates		206
Ivampah Master Holdings LLC
Investments Accounted for by the Equity Method
Equity investments in affiliates		$ 16
Economic interest in equity method investments (as a percent)		54.50%
Number of solar electric generating projects | project		3
Generation capacity (in MW) | MW		393
Release of reserve funds	$ 95
Decrease in assets due to deconsolidation				$ 1,300
Decrease in liabilities due to deconsolidation			$ 1,200