Note 9 - Concentrations of Credit Risk	6 Months Ended
Jun. 30, 2023
Notes to Financial Statements
Concentration Risk Disclosure [Text Block]	Note 9. Concentrations of credit risk The Company’s debt investments consist primarily of loans to development-stage companies at various stages of development in the technology, life science, healthcare information and services and sustainability industries. Many of these companies may have relatively limited operating histories and also may experience variation in operating results. Many of these companies conduct business in regulated industries and could be affected by changes in government regulations. Most of the Company’s borrowers will need additional capital to satisfy their continuing working capital needs and other requirements, and in many instances, to service the interest and principal payments on the loans. The Company’s largest debt investments may vary from period to period as new debt investments are recorded and existing debt investments are repaid. The Company’s five largest debt investments, at cost and fair value, represented 25% and 23% of total debt investments outstanding as of June 30, 2023 and December 31, 2022. No single debt investment represented more than 10% of the total debt investments at cost or fair value as of June 30, 2023 and December 31, 2022. Investment income, consisting of interest and fees, can fluctuate significantly upon repayment of large debt investments. Interest income from the five largest debt investments at cost accounted for 23% and 22% of total interest and fee income on investments for the three months ended June 30, 2023 and 2022, respectively. Interest income from the five largest debt investments at fair value accounted for 23% of total interest and fee income on investments for the three months ended June 30, 2023 and 2022. Interest income from the five largest debt investments at cost accounted for 23% and 22% of total interest and fee income on investments for the six months ended June 30, 2023 and 2022, respectively. Interest income from the five largest debt investments at fair value accounted for 23% and 22% of total interest and fee income on investments for the six months ended June 30, 2023 and 2022, respectively.

Note 9 - Concentrations of Credit Risk

6 Months Ended

Jun. 30, 2023

Concentration Risk Disclosure [Text Block]

Note 9. Concentrations of credit risk

The Company’s debt investments consist primarily of loans to development-stage companies at various stages of development in the technology, life science, healthcare information and services and sustainability industries. Many of these companies may have relatively limited operating histories and also may experience variation in operating results. Many of these companies conduct business in regulated industries and could be affected by changes in government regulations. Most of the Company’s borrowers will need additional capital to satisfy their continuing working capital needs and other requirements, and in many instances, to service the interest and principal payments on the loans.

The Company’s largest debt investments may vary from period to period as new debt investments are recorded and existing debt investments are repaid. The Company’s five largest debt investments, at cost and fair value, represented 25% and 23% of total debt investments outstanding as of June 30, 2023 and December 31, 2022. No single debt investment represented more than 10% of the total debt investments at cost or fair value as of June 30, 2023 and December 31, 2022. Investment income, consisting of interest and fees, can fluctuate significantly upon repayment of large debt investments. Interest income from the five largest debt investments at cost accounted for 23% and 22% of total interest and fee income on investments for the three months ended June 30, 2023 and 2022, respectively. Interest income from the five largest debt investments at fair value accounted for 23% of total interest and fee income on investments for the three months ended June 30, 2023 and 2022. Interest income from the five largest debt investments at cost accounted for 23% and 22% of total interest and fee income on investments for the six months ended June 30, 2023 and 2022, respectively. Interest income from the five largest debt investments at fair value accounted for 23% and 22% of total interest and fee income on investments for the six months ended June 30, 2023 and 2022, respectively.