Fair Value (Instruments Not Measured at Fair Value) (Details) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Carrying Amount [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	$ 252	$ 264
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		15,834	15,792
Recourse debt		4,500	4,671
Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Value added tax		38	24
Accounts receivable - noncurrent	[1]	340	350
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		16,318	16,188
Recourse debt		4,723	4,899
Level 1 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	0	0
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		0	0
Recourse debt		0	0
Level 2 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	19	20
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		15,096	15,120
Recourse debt		4,723	4,899
Level 3 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	321	330
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		1,222	1,068
Recourse debt		$ 0	$ 0

[1] These amounts principally relate to amounts due from CAMMESA, the administrator of the wholesale electricity market in Argentina, 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 $38 million and $24 million as of March 31, 2017 and December 31, 2016, respectively.