Fair Value (Instruments Not Measured at Fair Value) (Details) - USD ($) $ in Millions		Sep. 30, 2021	Dec. 31, 2020
Carrying Amount [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	$ 80	$ 97
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		16,501	16,354
Recourse debt		3,395	3,446
Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Value added tax		2	4
Accounts receivable - noncurrent	[1]	162	197
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		18,644	18,403
Recourse debt		3,543	3,677
Level 1 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent		0	0
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		0	5
Recourse debt		0	0
Level 2 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent		0	0
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		18,615	15,301
Recourse debt		3,543	3,677
Level 3 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	162	197
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		29	3,097
Recourse debt		$ 0	$ 0

[1] These amounts primarily relate to amounts due from CAMMESA, the administrator of the wholesale electricity market in Argentina, and amounts impacted by the Stabilization Fund enacted by the Chilean government, and are included in Other noncurrent assets in the accompanying Condensed Consolidated Balance Sheets. The fair value and carrying amount of these receivables exclude VAT of $2 million and $4 million as of September 30, 2021 and December 31, 2020, respectively.