Revenue Disaggregation of Revenue (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues		$ 2,431	$ 2,625	$ 2,483	$ 2,650	$ 2,622	$ 2,837	$ 2,537	$ 2,740	$ 10,189	$ 10,736	$ 10,530
Regulated Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										2,979	2,885
Other non-606 revenue										49	54
Revenues										3,028	2,939
Non-regulated revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										6,555	7,075
Other non-606 revenue	[1]									606	722
Revenues										7,161	7,797
US and Utilities [Domain]
Disaggregation of Revenue [Line Items]
Revenues										4,058	4,230
US and Utilities [Domain] | Regulated Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										2,979	2,885
Other non-606 revenue										49	54
Revenues										3,028	2,939
US and Utilities [Domain] | Non-regulated revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										767	972
Other non-606 revenue	[1]									263	319
Revenues										1,030	1,291
South America [Member]
Disaggregation of Revenue [Line Items]
Revenues										3,208	3,533
South America [Member] | Regulated Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										0	0
Other non-606 revenue										0	0
Revenues										0	0
South America [Member] | Non-regulated revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										3,205	3,529
Other non-606 revenue	[1]									3	4
Revenues										3,208	3,533
MCAC [Member]
Disaggregation of Revenue [Line Items]
Revenues										1,882	1,728
MCAC [Member] | Regulated Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										0	0
Other non-606 revenue										0	0
Revenues										0	0
MCAC [Member] | Non-regulated revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										1,788	1,642
Other non-606 revenue	[1]									94	86
Revenues										1,882	1,728
EURASIA [Member]
Disaggregation of Revenue [Line Items]
Revenues										1,047	1,255
EURASIA [Member] | Regulated Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										0	0
Other non-606 revenue										0	0
Revenues										0	0
EURASIA [Member] | Non-regulated revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										799	943
Other non-606 revenue	[1]									248	312
Revenues										1,047	1,255
Corporate Other And Other Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues										(6)	(10)
Corporate Other And Other Eliminations [Member] | Regulated Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										0	0
Other non-606 revenue										0	0
Revenues										0	0
Corporate Other And Other Eliminations [Member] | Non-regulated revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax										(4)	(11)
Other non-606 revenue	[1]									(2)	1
Revenues										$ (6)	$ (10)

[1] Other non-regulated revenue primarily includes lease and derivative revenue not accounted for under ASC 606.