HA Sustainable Infrastructure Capital, Inc. Annual report pursuant to Section 13 and 15(d)

Securitization of Financial Assets - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Managed assets	$ 6,200,000,000	$ 5,300,000,000
Securitization credit losses	0	0	$ 0
Payment from debtors to securitization trust	123,979,000	71,601,000
Asset-backed Securities, Securitized Loans and Receivables
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Managed receivables	$ 4,100,000,000	$ 3,300,000,000
Maximum
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Annual servicing fees	0.20%
Discount Rate \| Minimum
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Discount rates to determine fair market value of underlying assets	0.03
Discount Rate \| Maximum
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Discount rates to determine fair market value of underlying assets	0.07
Financial Asset, Equal to or Greater than 90 Days Past Due
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Payment from debtors to securitization trust	$ 0