Segments and Geographic Information Segment and Geographic Information ( Revenue by Segment) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 2,560	$ 2,545	$ 2,217	$ 2,338	$ 2,431	$ 2,625	$ 2,483	$ 2,650	$ 9,660	$ 10,189	$ 10,736
US and Utilities SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									3,918	4,058	4,230
South America
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									3,159	3,208	3,533
MCAC [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									1,766	1,882	1,728
EURASIA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									828	1,047	1,255
Corporate and Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									(11)	(6)	(10)
Corporate, Non-Segment [Member] | Corporate and Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									231	46	41
Intersegment Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									(242)	(52)	(51)
Operating Segments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									9,660	10,189	10,736
Operating Segments [Member] | US and Utilities SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									3,918	4,058	4,230
Operating Segments [Member] | South America
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									3,159	3,208	3,533
Operating Segments [Member] | MCAC [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									1,766	1,882	1,728
Operating Segments [Member] | EURASIA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									$ 828	$ 1,047	$ 1,255