v3.8.0.1
Financial information by segment, Business sectors (Details)
ft³ / d in Millions
12 Months Ended
Jul. 20, 2017
MW
Feb. 28, 2017
mi
Dec. 31, 2017
ft³ / d
WindFarm
Plant
Line
SolarPlatform
mi
MW
Dec. 31, 2016
MW
Financial information by segment [Abstract]        
Length of transmission lines | mi   114    
Seville PV [Member]        
Financial information by segment [Abstract]        
Gross capacity       1
United States [Member] | Renewable Energy [Member] | Solana [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | Plant     1  
Gross capacity     280  
United States [Member] | Renewable Energy [Member] | Mojave [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | Plant     1  
Gross capacity     280  
Spain [Member] | Renewable Energy [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | SolarPlatform     8  
Spain [Member] | Renewable Energy [Member] | PS10/PS20 [Member]        
Financial information by segment [Abstract]        
Gross capacity     31  
Spain [Member] | Renewable Energy [Member] | Solacor 1 and Solacor 2 [Member]        
Financial information by segment [Abstract]        
Gross capacity     100  
Spain [Member] | Renewable Energy [Member] | Solaben 2 and 3 [Member]        
Financial information by segment [Abstract]        
Gross capacity     100  
Spain [Member] | Renewable Energy [Member] | Helioenergy 1 and 2 [Member]        
Financial information by segment [Abstract]        
Gross capacity     100  
Spain [Member] | Renewable Energy [Member] | Helios 1 and 2 [Member]        
Financial information by segment [Abstract]        
Gross capacity     100  
Spain [Member] | Renewable Energy [Member] | Solnova 1, 3 and 4 [Member]        
Financial information by segment [Abstract]        
Gross capacity     150  
Spain [Member] | Renewable Energy [Member] | Solaben 1 and 6 [Member]        
Financial information by segment [Abstract]        
Gross capacity     100  
Spain [Member] | Renewable Energy [Member] | Seville PV [Member]        
Financial information by segment [Abstract]        
Gross capacity     1  
South Africa [Member] | Renewable Energy [Member] | Kaxu [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | Plant     1  
Gross capacity     100  
Uruguay [Member] | Renewable Energy [Member] | Palmatir [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | WindFarm     1  
Gross capacity     50  
Uruguay [Member] | Renewable Energy [Member] | Cadonal [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | WindFarm     1  
Gross capacity     50  
Mexico [Member] | Efficient Natural Gas [Member] | ACT [Member]        
Financial information by segment [Abstract]        
Gross capacity     300  
Term of take-or-pay contract     20 years  
Peru [Member]        
Financial information by segment [Abstract]        
Gross capacity 4      
Peru [Member] | Electric Transmission [Member] | ATN, ATS and ATN2 [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | Line     3  
Length of transmission lines | mi     1,012  
Chile [Member] | Electric Transmission [Member] | Quadra 1, Quadra 2, and Palmucho [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | Line     3  
Length of transmission lines | mi     87  
Algeria [Member] | Water [Member] | Honaine and Skikda [Member]        
Financial information by segment [Abstract]        
Number of contracted assets | Plant     2  
Aggregate capacity | ft³ / d     10.5