Annual report pursuant to Section 13 and 15(d)

The Company - Summary of Unaudited Pro Forma Information (Detail)

v2.4.1.9
The Company - Summary of Unaudited Pro Forma Information (Detail) (AWCC [Member], USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
AWCC [Member]
   
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]    
Pro forma net investment revenue $ 31.9us-gaap_BusinessAcquisitionsProFormaRevenue
/ us-gaap_BusinessAcquisitionAxis
= hasi_AwccMember
$ 21.4us-gaap_BusinessAcquisitionsProFormaRevenue
/ us-gaap_BusinessAcquisitionAxis
= hasi_AwccMember
Pro forma net income $ 11.8us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
/ us-gaap_BusinessAcquisitionAxis
= hasi_AwccMember
$ (11.8)us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
/ us-gaap_BusinessAcquisitionAxis
= hasi_AwccMember