Annual report pursuant to Section 13 and 15(d)

Long-term Debt - Outstanding Non-Recourse Asset-Backed Debt and Bank Loans (Details)

v3.20.4
Long-term Debt - Outstanding Non-Recourse Asset-Backed Debt and Bank Loans (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Unamortized financing costs $ (12) $ (16)
Total 593 700
Collateral Pledged    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Restricted cash 23 24
Asset-Backed Non-recourse Debt    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Total collateral pledged against our nonrecourse debt 723 921
Asset-Backed Non-recourse Debt | HASI Sustainable Yield Bond 2015-1A    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Carrying value of Senior Unsecured Notes $ 81 85
Stated Interest Rate 4.28%  
Anticipated Balance at Maturity $ 0  
Carrying value of assets pledged, receivables 134 126
Asset-Backed Non-recourse Debt | HASI Sustainable Yield Bond 2015-1B Note    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Carrying value of Senior Unsecured Notes $ 13 13
Stated Interest Rate 5.41%  
Anticipated Balance at Maturity $ 0  
Carrying value of assets pledged, other 134 126
Asset-Backed Non-recourse Debt | Two Thousand Seventeen Credit Agreement    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Carrying value of Senior Unsecured Notes $ 0 61
Stated Interest Rate 4.12%  
Anticipated Balance at Maturity $ 0  
Carrying value of assets pledged, other 0 120
Asset-Backed Non-recourse Debt | Hannon Armstrong Sustainable Infrastructure Capital Sustainable Yield Bond Loan Agreement Two Thousand Fifteen Two    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Carrying value of Senior Unsecured Notes 0 28
Anticipated Balance at Maturity 0  
Carrying value of assets pledged, other 0 73
Asset-Backed Non-recourse Debt | HASI SYB Trust 2016-2    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Carrying value of Senior Unsecured Notes $ 67 72
Stated Interest Rate 4.35%  
Anticipated Balance at Maturity $ 0  
Carrying value of assets pledged, receivables 71 76
Asset-Backed Non-recourse Debt | HASI ECON 101 Trust    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Carrying value of Senior Unsecured Notes $ 126 129
Stated Interest Rate 3.57%  
Anticipated Balance at Maturity $ 0  
Carrying value of assets pledged, receivables 133 135
Asset-Backed Non-recourse Debt | HASI SYB Trust 2017-1    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Carrying value of Senior Unsecured Notes $ 150 155
Stated Interest Rate 3.86%  
Anticipated Balance at Maturity $ 0  
Carrying value of assets pledged, receivables 205 206
Asset-Backed Non-recourse Debt | Lannie Mae Series 2019-1    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Carrying value of Senior Unsecured Notes $ 95 96
Stated Interest Rate 3.68%  
Anticipated Balance at Maturity $ 0  
Carrying value of assets pledged, receivables 107 106
Other Non-recourse Debt    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Other non-recourse debt 73 77
Anticipated Balance at Maturity 18  
Carrying value of assets pledged, receivables $ 73 $ 77
Other Non-recourse Debt | Minimum    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Stated Interest Rate 3.15%  
Other Non-recourse Debt | Maximum    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Stated Interest Rate 7.45%