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

Our Portfolio - Equity Method Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 458,916	$ 471,044
2007 Vento I, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value	93,000
Buckeye Wind Energy Class B Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value	71,000
Northern Frontier Wind, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value	65,000
3D Engie, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value	49,000
Invenergy Gunsight Mountain Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value	37,000
Helix Fund, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value	26,000
Other Transactions [Member]
Schedule of Equity Method Investments [Line Items]
Carrying Value	$ 118,000