Segments and Geographic Information Segment and Geographic Information ( Revenue by Segment) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 2,622	$ 2,837	$ 2,537	$ 2,740	$ 2,643	$ 2,693	$ 2,613	$ 2,581	$ 10,736	$ 10,530	$ 10,281
US and Utilities SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									4,230
South America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									3,533
MCAC [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									1,728
EURASIA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									1,255
Corporate, Other and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									(10)
Corporate, Non-Segment [Member] | Corporate, Other and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									41	35	77
Intersegment Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									(51)	(28)	(26)
Operating Segments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									10,736	10,530	10,281
Operating Segments [Member] | US and Utilities SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									4,230	4,162	4,330
Operating Segments [Member] | South America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									3,533	3,252	2,956
Operating Segments [Member] | MCAC [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									1,728	1,519	1,274
Operating Segments [Member] | EURASIA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									$ 1,255	$ 1,590	$ 1,670