Consolidated Schedule of Investments (Unaudited) - Investments (Details) (Parentheticals)	Jun. 30, 2025	Dec. 31, 2024
NAV %	219.40%	207.60%
Unrestricted Short Term Investments [Member]
NAV %	18.80%	8.10%
Restricted Short Term Investments [Member]
NAV %	1.10%	1.00%
Investment, Affiliated Issuer, Controlled [Member]
NAV %	3.70%	9.50%
Investment, Affiliated Issuer, Controlled [Member] \| Debt Securities [Member]
NAV %	0.30%	2.30%
Investment, Affiliated Issuer, Controlled [Member] \| Other Investments [Member]
NAV %	0.60%	1.90%
Investment, Affiliated Issuer, Controlled [Member] \| Equity Securities [Member]
NAV %	2.80%	5.30%
Investment, Affiliated Issuer, Noncontrolled [Member] \| Other Investments [Member]
NAV %	2.40%	2.50%
Investment, Affiliated Issuer, Noncontrolled [Member] \| Equity Securities [Member]
NAV %	0.00%	0.00%
Investment, Affiliated Issuer, Noncontrolled [Member] \| Warrant [Member]
NAV %	0.00%	0.00%
Investment, Unaffiliated Issuer [Member]
NAV %	213.30%	195.60%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member]
NAV %	203.80%	187.70%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Sustainability Segment [Member]
NAV %	10.20%	19.90%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Life Science Segment [Member]
NAV %	97.20%	77.80%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Technology Sector [Member]
NAV %	61.00%	59.00%
Investment, Unaffiliated Issuer [Member] \| Debt Securities [Member] \| Healthcare Information and Services Segment [Member]
NAV %	35.40%	31.00%
Investment, Unaffiliated Issuer [Member] \| Other Investments [Member] \| Life Science Segment [Member]
NAV %	0.00%	0.00%
Investment, Unaffiliated Issuer [Member] \| Equity Securities [Member]
NAV %	1.90%	2.50%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member]
NAV %	7.60%	5.40%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Sustainability Segment [Member]
NAV %	0.00%	0.10%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Life Science Segment [Member]
NAV %	2.10%	1.90%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Technology Sector [Member]
NAV %	4.40%	3.10%
Investment, Unaffiliated Issuer [Member] \| Warrant [Member] \| Healthcare Information and Services Segment [Member]
NAV %	1.10%	0.30%