Capitalization - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended
	Mar. 31, 2019	Feb. 28, 2019	Mar. 31, 2019	Dec. 31, 2018
Schedule of Capitalization [Line Items]
Number of shares of common stock issued (shares)	5,649,369
Issuance of common shares – public offering	$ 425,000,000		$ 425,000,000
Term loan	0		0	$ 825,000,000
PG&E Project
Schedule of Capitalization [Line Items]
Term loan	$ 1,041,000,000		$ 1,041,000,000
Clean Energy Businesses
Schedule of Capitalization [Line Items]
Non-recourse debt				2,076,000,000
Clean Energy Businesses | Long-term debt due within one year
Schedule of Capitalization [Line Items]
Non-recourse debt				1,965,000,000
Clean Energy Businesses | Long-term debt
Schedule of Capitalization [Line Items]
Non-recourse debt				$ 111,000,000
Term Loan
Schedule of Capitalization [Line Items]
Face amount of debt		$ 825,000,000
Debt term		2 years