Annual report pursuant to Section 13 and 15(d)

Equity - Additional Information (Detail)

v2.4.1.9
Equity - Additional Information (Detail) (USD $)
0 Months Ended 1 Months Ended 12 Months Ended 9 Months Ended
Apr. 23, 2013
Aug. 31, 2014
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2013
Oct. 31, 2014
Apr. 29, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Registration of IPO Common Stock, date registered     Aug. 31, 2014        
Sale of stock, description of transaction     In August 2014, we filed a registration statement with the SEC registering the resale, from time to time, by certain persons of up to 3,178,410 shares of common stock, comprised of: (1) 1,741,238 shares of common stock issued in connection with our formation transactions at the time of our IPO, (2) 331,282 shares of common stock issuable upon exchange of OP units issued in connection with our formation transactions, which are exchangeable on a one-for-one basis, into cash or, at our option, shares of our common stock and (3) 1,105,890 shares of common stock granted under the 2013 Plan to our directors, officers and other employees.        
Proceeds from the sale of the shares   $ 0us-gaap_ProceedsFromIssuanceOrSaleOfEquity $ 129,351,000us-gaap_ProceedsFromIssuanceOrSaleOfEquity $ 160,031,000us-gaap_ProceedsFromIssuanceOrSaleOfEquity      
Sale of Stock, Cost   100,000hasi_SaleOfStockIssuanceCosts          
Sale of common stock, value     129,351,000us-gaap_StockIssuedDuringPeriodValueNewIssues 157,981,000us-gaap_StockIssuedDuringPeriodValueNewIssues      
First follow-on public offering, shares           4,600,000hasi_FollowOnPublicOfferingShares 5,750,000hasi_FollowOnPublicOfferingShares
Share issued pursuant to underwriter           600,000hasi_CommonStockSharesIssuedPursuantToUnderwritersOption 750,000hasi_CommonStockSharesIssuedPursuantToUnderwritersOption
First follow-on public offering, price per share           $ 13.60hasi_FollowOnPublicOfferingSharesPrice $ 13.00hasi_FollowOnPublicOfferingSharesPrice
Net proceeds from first follow-on from public offering           58,900,000hasi_ProceedsFromIssuanceOfFollowOnPublicOfferingNet 70,400,000hasi_ProceedsFromIssuanceOfFollowOnPublicOfferingNet
Number of shares received by employees through reallocation 202,826hasi_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesReallocated            
Value per share under stock based compensation plan $ 12.50us-gaap_SaleOfStockPricePerShare            
Compensation expense 5,800,000us-gaap_StockOptionPlanExpense            
Income tax benefits on reallocation 0hasi_IncomeTaxBenefitDueToImpactOfValuationAllowance            
Number of restricted common stock granted 606,415hasi_RestrictedStockUnitsGrantedDuringPeriod            
Restricted common stock vesting period 4 years            
Scenario Forecast [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Sale of stock   3,178,410us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
         
Shares of common stock issued in connection formation transactions   1,741,238us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
         
Shares of common stock granted to directors, officers and other employees   1,105,890us-gaap_StockIssuedDuringPeriodSharesEmployeeStockOwnershipPlan
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
         
Sale of common stock, value   500,000,000us-gaap_StockIssuedDuringPeriodValueNewIssues
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
         
Scenario Forecast [Member] | Directors, Officers and Other Employees [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Common stock exchangeable ratio     Exchangeable on a one-for-one basis, into cash or, at our option, shares of our common stock        
OP Units [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Number of shares received by employees through reallocation 135,938hasi_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesReallocated
/ us-gaap_AwardTypeAxis
= hasi_OperatingPartnershipUnitsMember
           
OP Units [Member] | Scenario Forecast [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Shares of common stock issuable upon exchange of OP units issued   331,282us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits
/ us-gaap_AwardTypeAxis
= hasi_OperatingPartnershipUnitsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
         
Performance Based Restricted Stock Award [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Number of shares received by employees through reallocation 128,348hasi_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesReallocated
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
           
Restricted Common Stock [Member] | 2013 Plan [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Equity-based compensation shares vested       0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= hasi_RestrictedCommonStockMember
/ us-gaap_PlanNameAxis
= hasi_TwoThousandAndThirteenStockCompensationPlanMember
     
Shares awarded       379,741us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures
/ us-gaap_AwardTypeAxis
= hasi_RestrictedCommonStockMember
/ us-gaap_PlanNameAxis
= hasi_TwoThousandAndThirteenStockCompensationPlanMember
     
Restricted Common Stock [Member] | 2013 Plan [Member] | Employees and Directors [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Shares awarded     149,359us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures
/ us-gaap_AwardTypeAxis
= hasi_RestrictedCommonStockMember
/ us-gaap_PlanNameAxis
= hasi_TwoThousandAndThirteenStockCompensationPlanMember
/ us-gaap_TitleOfIndividualAxis
= hasi_EmployeesAndDirectorsMember
       
Restricted common shares vesting years     Vest in 2015 through 2018        
Restricted Common Stock [Member] | 2013 Plan [Member] | Certain Employees [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Shares awarded     379,741us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures
/ us-gaap_AwardTypeAxis
= hasi_RestrictedCommonStockMember
/ us-gaap_PlanNameAxis
= hasi_TwoThousandAndThirteenStockCompensationPlanMember
/ us-gaap_TitleOfIndividualAxis
= hasi_OtherEmployeesMember
       
Restricted Incentive [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Equity-based compensation shares vested     149,709us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
       
Restricted Incentive [Member] | 2013 Plan [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Assumed forfeiture rate for calculation of compensation expense     5.00%hasi_ExpectedForfeitureRateInDeterminingShareBasedCompensationExpense
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_PlanNameAxis
= hasi_TwoThousandAndThirteenStockCompensationPlanMember
       
Equity-based compensation expense     5,200,000us-gaap_EmployeeBenefitsAndShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_PlanNameAxis
= hasi_TwoThousandAndThirteenStockCompensationPlanMember
  7,100,000us-gaap_EmployeeBenefitsAndShareBasedCompensation
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_PlanNameAxis
= hasi_TwoThousandAndThirteenStockCompensationPlanMember
   
Unrecognized compensation expense     $ 8,900,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_PlanNameAxis
= hasi_TwoThousandAndThirteenStockCompensationPlanMember
       
Weighted-average term in which unrecognized compensation expense is expected to be recognized     2 years