Hannon Armstrong Sustainable Infrastructure Capital, Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

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

Long-term Debt - Schedule of Outstanding Non-Recourse Asset-Backed Debt and Bank Loans (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Financial Instruments Owned and Pledged as Collateral [Line Items]
Debt issuance costs	$ (21)
Value of Assets Pledged, Equity interest	$ 29	$ 41
Minimum [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	2.26%
Non-recourse Asset-Backed Debt, Maturity Date	2017-12
Maximum [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	7.45%
Non-recourse Asset-Backed Debt, Maturity Date	2046-12
HASI Sustainable Yield Bond 2013-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	2.79%
Non-recourse Asset-Backed Debt, Maturity Date	2019-12
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 57
ABS Loan Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	5.74%
Non-recourse Asset-Backed Debt, Maturity Date	2021-09
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 17
HASI Sustainable Yield Bond 2015-1A [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.28%
Non-recourse Asset-Backed Debt, Maturity Date	2034-10
HASI Sustainable Yield Bond 2015-1B [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	5.41%
Non-recourse Asset-Backed Debt, Maturity Date	2034-10
2017 Credit Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	3.55%
Non-recourse Asset-Backed Debt, Maturity Date	2024-06
HASI SYB Loan Agreement 2015-2 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	5.41%
Non-recourse Asset-Backed Debt, Maturity Date	2023-12
HASI SYB Loan Agreement 2015-3 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.92%
Non-recourse Asset-Backed Debt, Maturity Date	2020-12
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 127
HASI SYB Loan Agreement 2016-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.37%
Non-recourse Asset-Backed Debt, Maturity Date	2021-11
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 101
HASI SYB Trust 2016-2 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.35%
Non-recourse Asset-Backed Debt, Maturity Date	2037-04
2017 Master Repurchase Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	3.96%
Non-recourse Asset-Backed Debt, Maturity Date	2019-07
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 31
HASI ECON 101 Trust [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	3.57%
Non-recourse Asset-Backed Debt, Maturity Date	2041-05
Asset-Backed Nonrecourse Debt Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Other non-recourse debt	$ 85	84
Debt issuance costs	(21)	(17)
Outstanding Balance	1,076	692
Value of Assets Pledged, Equity interest	$ 224	81
Description of Assets Pledged	Financing receivables
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI Sustainable Yield Bond 2013-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 68	75
Value of Assets Pledged, Equity interest	$ 87	93
Description of Assets Pledged	Financing receivables
Asset-Backed Nonrecourse Debt Agreement [Member] \| ABS Loan Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 79	90
Value of Assets Pledged, Equity interest	$ 80	97
Description of Assets Pledged	Equity interest in Strong Upwind Holdings I, LLC
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI Sustainable Yield Bond 2015-1A [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 95	97
Non-recourse Asset-Backed Debt, Interest Rate	4.28%
Non-recourse Asset-Backed Debt, Maturity Date	2034-10
Value of Assets Pledged, Equity interest	$ 137	138
Description of Assets Pledged	Financing receivables, real estate and real estate intangibles
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI Sustainable Yield Bond 2015-1B [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 14
Non-recourse Asset-Backed Debt, Interest Rate	5.00%
Non-recourse Asset-Backed Debt, Maturity Date	2034-10
Value of Assets Pledged, Equity interest	$ 137
Description of Assets Pledged	Class B Bond of HASI Sustainable Yield Bond 2015-1
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI SYB Loan Agreement 2015-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance		74
Value of Assets Pledged, Equity interest		96
Description of Assets Pledged	Equity interest in Strong Upwind Holdings II and III, LLC, related interest rate swap
Asset-Backed Nonrecourse Debt Agreement [Member] \| 2017 Credit Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 198
Value of Assets Pledged, Equity interest	$ 243
Description of Assets Pledged	Equity interests in Strong Upwind Holdings I, II, III, and IV LLC, and Northern Frontier, LLC
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI SYB Loan Agreement 2015-2 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 37	41
Value of Assets Pledged, Equity interest	$ 67	70
Description of Assets Pledged	Equity interest in Buckeye Wind Energy Class B Holdings LLC, related interest rate swap
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI SYB Loan Agreement 2015-3 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 146	150
Value of Assets Pledged, Equity interest	$ 172	175
Description of Assets Pledged	Residential solar financing receivables, related interest rate swaps
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI SYB Loan Agreement 2016-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 118	98
Value of Assets Pledged, Equity interest	$ 138	$ 114
Description of Assets Pledged	Residential solar financing receivables, related interest rate swaps
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI SYB Trust 2016-2 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 86
Value of Assets Pledged, Equity interest	$ 88
Description of Assets Pledged	Financing receivables
Asset-Backed Nonrecourse Debt Agreement [Member] \| 2017 Master Repurchase Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 37
Value of Assets Pledged, Equity interest	$ 41
Description of Assets Pledged	Financing receivables and investments
Asset-Backed Nonrecourse Debt Agreement [Member] \| HASI ECON 101 Trust [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 134
Value of Assets Pledged, Equity interest	$ 139
Description of Assets Pledged	Financing receivables and investments