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Our Portfolio - Financing Receivables, Investments, Real Estate and Equity Method Investments - Components of Real Estate Portfolio (Detail)

v2.4.1.9
Our Portfolio - Financing Receivables, Investments, Real Estate and Equity Method Investments - Components of Real Estate Portfolio (Detail) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Real Estate Properties [Line Items]    
Accumulated amortization of real estate intangibles $ (1)us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation $ 0us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation
Real Estate 130us-gaap_RealEstateInvestmentPropertyNet 114us-gaap_RealEstateInvestmentPropertyNet
Land [Member]    
Real Estate Properties [Line Items]    
Real Estate 106us-gaap_RealEstateInvestmentPropertyNet
/ us-gaap_RealEstatePropertiesAxis
= us-gaap_LandMember
91us-gaap_RealEstateInvestmentPropertyNet
/ us-gaap_RealEstatePropertiesAxis
= us-gaap_LandMember
Real Estate Related Intangibles [Member]    
Real Estate Properties [Line Items]    
Real Estate $ 25us-gaap_RealEstateInvestmentPropertyNet
/ us-gaap_RealEstatePropertiesAxis
= hasi_RealEstateRelatedIntangiblesMember
$ 23us-gaap_RealEstateInvestmentPropertyNet
/ us-gaap_RealEstatePropertiesAxis
= hasi_RealEstateRelatedIntangiblesMember