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Consolidated Schedule of Investments (Unaudited) - Investments (Details) (Parentheticals)	Mar. 31, 2023	Dec. 31, 2022
NAV %	222.40%	226.10%
Investment, Unaffiliated Issuer [Member]
NAV %	221.10%	226.10%
Investment, Unaffiliated Issuer [Member] | Warrant [Member]
NAV %	8.00%	9.40%
Investment, Unaffiliated Issuer [Member] | Warrant [Member] | Healthcare Sector [Member]
NAV %	0.60%	0.60%
Investment, Unaffiliated Issuer [Member] | Warrant [Member] | Life Science [Member]
NAV %	2.10%	3.10%
Investment, Unaffiliated Issuer [Member] | Warrant [Member] | Sustainability Segment [Member]
NAV %	0.20%	0.60%
Investment, Unaffiliated Issuer [Member] | Warrant [Member] | Technology Sector [Member]
NAV %	5.10%	5.10%
Investment, Unaffiliated Issuer [Member] | Other Long-Term Investments [Member]
NAV %	0.40%	0.40%
Investment, Unaffiliated Issuer [Member] | Equity Securities [Member]
NAV %	0.90%	0.80%
Investment, Unaffiliated Issuer [Member] | Debt Securities [Member]
NAV %	212.80%	215.50%
Investment, Unaffiliated Issuer [Member] | Debt Securities [Member] | Healthcare Sector [Member]
NAV %	8.10%	8.10%
Investment, Unaffiliated Issuer [Member] | Debt Securities [Member] | Life Science [Member]
NAV %	95.70%	99.70%
Investment, Unaffiliated Issuer [Member] | Debt Securities [Member] | Sustainability Segment [Member]
NAV %	25.80%	26.30%
Investment, Unaffiliated Issuer [Member] | Debt Securities [Member] | Technology Sector [Member]
NAV %	83.20%	81.40%
Investment, Affiliated Issuer, Noncontrolled [Member]
NAV %	0.30%
Investment, Affiliated Issuer, Noncontrolled [Member] | Equity Securities [Member] | Life Science [Member]
NAV %	0.30%

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