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

Annual report pursuant to Section 13 and 15(d)

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Summary of Significant Accounting Policies (Policies)
Notes Tables
Notes Details

Securitization of Receivables - Additional Information (Detail)

v3.8.0.1

Securitization of Receivables - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Managed receivables	$ 4,700,000,000	$ 3,900,000,000
Securitization credit losses	0	0	$ 0
Asset-backed Securities, Securitized Loans and Receivables [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Managed receivables	2,700,000,000	$ 2,300,000,000
Greater than 90 Days Past Due [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Payment from debtors to securitization trust	$ 1,100,000
Minimum [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Discount rates to determine fair market value of underlying assets	4.00%
Maximum [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Annual servicing fees	0.20%
Discount rates to determine fair market value of underlying assets	7.00%

- Definition

Receivables Serviced

+ References

No definition available.

+ Details

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Namespace Prefix:	hasi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Services Fee Annual Rate

+ References

No definition available.

+ Details

Name:	hasi_ServicesFeeAnnualRate
Namespace Prefix:	hasi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount owed to the reporting entity by counterparties in securitized loan transactions.

+ References

No definition available.

+ Details

Name:	us-gaap_AccountsReceivableFromSecuritization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueInputsDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of credit loss after recoveries for transferred financial assets that continue to be recognized in the statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (e)(5)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=d3e107314-111719

+ Details

Name:	us-gaap_NetCreditLossOnLoansManagedOrSecuritizedOrAssetbackedFinancingArrangement
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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