Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Schedule of Residual Interests Securitized Receivables and Derivatives Carried at Fair Value (Parenthetical) (Detail)

v2.4.1.9
Fair Value Measurements - Schedule of Residual Interests Securitized Receivables and Derivatives Carried at Fair Value (Parenthetical) (Detail) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Sep. 30, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Allowance for loan losses on financing receivables $ 1,200,000us-gaap_FinancingReceivableAllowanceForCreditLosses $ 11,000,000us-gaap_FinancingReceivableAllowanceForCreditLosses $ 0us-gaap_FinancingReceivableAllowanceForCreditLosses
Amortized costs 26,900,000us-gaap_AvailableForSaleSecuritiesAmortizedCost    
Financing Receivable [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Net fair value collateral impaired loan 800,000hasi_FairValueCollateralImpairedLoanNet
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_FinanceReceivablesMember
800,000hasi_FairValueCollateralImpairedLoanNet
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_FinanceReceivablesMember
 
Allowance for loan losses on financing receivables $ 1,200,000us-gaap_FinancingReceivableAllowanceForCreditLosses
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_FinanceReceivablesMember
$ 11,000,000us-gaap_FinancingReceivableAllowanceForCreditLosses
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_FinanceReceivablesMember