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

Equity - Additional Information (Detail)

v3.3.0.814

Equity - Additional Information (Detail) - 2013 Plan [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Restricted Common Stock [Member] \| Employees and Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded			196,517
Restricted common shares vesting years			Vest in 2015 to 2019
Restricted Common Stock [Member] \| Certain Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded			390,131
Restricted Incentive [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 2.7	$ 1.7	$ 7.7	$ 3.6
Unrecognized compensation expense	$ 11.8		$ 11.8
Weighted-average term in which unrecognized compensation expense is expected to be recognized			2 years
Assumed forfeiture rate for calculation of equity-based compensation expense			5.00%

- Definition

Expected Forfeiture Rate In Determining Share Based Compensation Expense

+ References

No definition available.

+ Details

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

- Definition

Share Based Compensation Arrangement By Share Based Payment Restricted Stock Awards Vesting Date

+ References

No definition available.

+ Details

Name:	hasi_ShareBasedCompensationArrangementByShareBasedPaymentRestrictedStockAwardsVestingDate
Namespace Prefix:	hasi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Stock Based Compensation Not Yet Recognized Weighted Average Period Of Expected Recognition

+ References

No definition available.

+ Details

Name:	hasi_StockBasedCompensationNotYetRecognizedWeightedAveragePeriodOfExpectedRecognition
Namespace Prefix:	hasi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Costs and payments related to employee benefits and equity-based compensation, such as pension expense and contributions, other postretirement benefits expense and payments, stock or unit options expense, and amortization of restricted stock or unit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

+ Details

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

- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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

- 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

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

- Definition

Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=hasi_RestrictedCommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=hasi_TwoThousandAndThirteenStockCompensationPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=hasi_EmployeesAndDirectorsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=hasi_OtherEmployeesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: