Consolidated Schedule of Investments (Unaudited) - Investments (Details) (Parentheticals)	Sep. 30, 2023	Dec. 31, 2022
NAV %	210.40%	226.10%
Investment, Affiliated Issuer, Controlled [Member] \| Debt Securities [Member]
NAV %	3.80%
Investment, Affiliated Issuer, Controlled [Member] \| Debt Securities [Member] \| Consumer-related Technologies [Member]
NAV %	1.30%
Investment, Affiliated Issuer, Controlled [Member] \| Preferred and Common Stock [Member] \| Technology Sector [Member]
NAV %	0.70%
Investment, Affiliated Issuer, Controlled [Member] \| Other Investments [Member] \| Biotechnology Sector [Member]
NAV %	1.80%
Investment, Affiliated Issuer, Noncontrolled [Member]
NAV %	5.90%
Investment, Affiliated Issuer, Noncontrolled [Member] \| Debt Securities [Member] \| Life Science [Member]
NAV %	3.50%
Investment, Affiliated Issuer, Noncontrolled [Member] \| Equity Securities [Member] \| Life Science [Member]
NAV %	2.40%
Investment, Affiliated Issuer, Noncontrolled [Member] \| Warrant [Member] \| Life Science [Member]
NAV %	0.00%
Investment, Unaffiliated Issuer [Member]
NAV %	200.70%	226.10%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member]
NAV %	191.40%	215.50%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Life Science [Member]
NAV %	69.70%	99.70%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Technology Sector [Member]
NAV %	80.50%	81.40%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Other Sustainability Sector [Member]
NAV %	23.80%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Sustainability Segment [Member]
NAV %		26.30%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Healthcare Sector [Member]
NAV %	17.40%	8.10%
Investment, Unaffiliated Issuer [Member] \| Equity Securities [Member]
NAV %	1.40%	0.80%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member]
NAV %	7.60%	9.40%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Life Science [Member]
NAV %		3.10%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Technology Sector [Member]
NAV %	4.70%	5.10%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Healthcare Information and Services Segment [Member]
NAV %	0.60%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Life Science Segment [Member]
NAV %	2.00%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Sustainability Segment [Member]
NAV %	0.20%	0.60%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Healthcare Sector [Member]
NAV %		0.60%
Investment, Unaffiliated Issuer [Member] \| Other Long-Term Investments [Member]
NAV %		0.40%
Investment, Unaffiliated Issuer [Member] \| Other Long-Term Investments [Member] \| Life Science [Member]
NAV %	0.30%