Goodwill and Other Intangible Assets (Goodwill Roll Forward) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill	$ 3,672	$ 3,670
Accumulated impairment losses	(2,611)	(2,611)
Net balance	1,061	1,059
Operating Segments [Member] | ANDES [Member]
Goodwill [Roll Forward]
Goodwill	868	868
Accumulated impairment losses	0	0
Net balance	868	868
Operating Segments [Member] | MCAC [Member]
Goodwill [Roll Forward]
Goodwill	16	16
Accumulated impairment losses	0	0
Net balance	16	16
Operating Segments [Member] | EURASIA [Member]
Goodwill [Roll Forward]
Goodwill	0	0
Accumulated impairment losses	0	0
Net balance	0	0
Operating Segments [Member] | US and Utilities SBU
Goodwill [Roll Forward]
Goodwill	2,788	2,786
Accumulated impairment losses	(2,611)	(2,611)
Net balance	$ 177	$ 175