Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v3.8.0.1
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2017
Oct. 30, 2017
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q3  
Trading Symbol HASI  
Entity Registrant Name Hannon Armstrong Sustainable Infrastructure Capital, Inc.  
Entity Central Index Key 0001561894  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   53,067,158