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

Securitization of Receivables - Summary of Certain Transactions with Securitization Trusts (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Gains on securitizations	$ 11,061	$ 7,095
Securitization Trust [Member]
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Gains on securitizations	12,000	10,000
Purchase of receivables securitized	195,000	319,000
Proceeds from securitizations	207,000	329,000
Cash received from residual and servicing assets	3,000	2,000
Securitization Trust [Member] \| Residual Assets [Member]
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Residual and servicing assets included in Other Assets	$ 29,000	$ 15,000