v3.10.0.1
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2018
Jul. 31, 2018
Document and Entity Information [Abstract]    
Entity Registrant Name TerraForm Power, Inc.  
Entity Central Index Key 0001599947  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Jun. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   209,061,636