Annual report pursuant to Section 13 and 15(d)

Defined Contribution Plan - Additional Information (Detail)

v2.4.1.9
Defined Contribution Plan - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Sep. 30, 2012
Defined Contribution Benefit Plans [Line Items]      
Contribution plan cost $ 0.2us-gaap_DefinedContributionPlanCostRecognized $ 0.2us-gaap_DefinedContributionPlanCostRecognized $ 0.1us-gaap_DefinedContributionPlanCostRecognized
Defined contribution plan matching contribution, Description Under the plan, we provide a dollar for dollar match for the first 3% of the employee's contributions and a $0.50 per dollar match for the next 2% of employee contributions.    
First 3% of Employee's Contribution [Member]      
Defined Contribution Benefit Plans [Line Items]      
Defined contribution plan employer's matching contribution, Percentage of match 100.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= hasi_LevelOneMember
   
Next 2% of Employee's Contribution [Member]      
Defined Contribution Benefit Plans [Line Items]      
Defined contribution plan employer's matching contribution, Percentage of match 50.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= hasi_LevelsTwoMember