Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Long-term Debt - Schedule of Outstanding Non-Recourse Asset-Backed Debt and Bank Loans (Details) - USD ($)
$ in Millions
Sep. 30, 2018
Dec. 31, 2017
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Debt issuance costs $ (24) $ (27)
Total debt 1,096 1,211
Value of Assets Pledged, Other   29
Asset-Backed Non-recourse Debt [Member] | HASI Sustainable Yield Bond 2013-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 62 67
Interest Rate 2.79%  
Anticipated Balance at Maturity $ 57  
Value of Assets Pledged, Receivables 83 86
Asset-Backed Non-recourse Debt [Member] | ABS Loan Agreement [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 0 81
Interest Rate 5.74%  
Anticipated Balance at Maturity $ 0  
Value of Assets Pledged, Other 0 79
Asset-Backed Non-recourse Debt [Member] | HASI Sustainable Yield Bond 2015-1A [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 91 94
Interest Rate 4.28%  
Anticipated Balance at Maturity $ 0  
Value of Assets Pledged, Receivables 135 137
Asset-Backed Non-recourse Debt [Member] | HASI Sustainable Yield Bond 2015-1B Note [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 13 14
Interest Rate 5.41%  
Anticipated Balance at Maturity $ 0  
Value of Assets Pledged, Other 135 137
Asset-Backed Non-recourse Debt [Member] | 2017 Credit Agreement [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 124 180
Interest Rate 4.12%  
Anticipated Balance at Maturity $ 0  
Value of Assets Pledged, Other 160 226
Asset-Backed Non-recourse Debt [Member] | HASI SYB Loan Agreement 2015-2 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 33 36
Interest Rate 6.47%  
Anticipated Balance at Maturity $ 0  
Value of Assets Pledged, Other 72 68
Asset-Backed Non-recourse Debt [Member] | HASI SYB Loan Agreement 2015-3 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 137 143
Interest Rate 4.92%  
Anticipated Balance at Maturity $ 127  
Value of Assets Pledged, Receivables 167 171
Asset-Backed Non-recourse Debt [Member] | HASI SYB Loan Agreement 2016-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 119 121
Interest Rate 5.40%  
Anticipated Balance at Maturity $ 106  
Value of Assets Pledged, Receivables 141 143
Asset-Backed Non-recourse Debt [Member] | HASI SYB Trust 2016-2 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 81 81
Interest Rate 4.35%  
Anticipated Balance at Maturity $ 0  
Value of Assets Pledged, Receivables 82 86
Asset-Backed Non-recourse Debt [Member] | 2017 Master Repurchase Agreement [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 47 35
Interest Rate 5.00%  
Anticipated Balance at Maturity $ 42  
Value of Assets Pledged, Receivables 51 38
Asset-Backed Non-recourse Debt [Member] | HASI ECON 101 Trust [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 133 134
Interest Rate 3.57%  
Anticipated Balance at Maturity $ 0  
Value of Assets Pledged, Receivables 135 140
Asset-Backed Non-recourse Debt [Member] | HASI SYB Trust 2017-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 160 162
Interest Rate 3.86%  
Anticipated Balance at Maturity $ 0  
Value of Assets Pledged, Receivables 208 209
Other Non-recourse Debt [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Other non-recourse debt 120 90
Anticipated Balance at Maturity 18  
Value of Assets Pledged, Receivables $ 177 $ 162
Other Non-recourse Debt [Member] | Minimum [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Interest Rate 2.26%  
Other Non-recourse Debt [Member] | Maximum [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Interest Rate 7.45%