Note 6 - Fair Value - Assets at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Recurring [Member]
Investments, fair value	$ 695,697	$ 647,244
Fair Value, Recurring [Member] \| Debt [Member]
Investments, fair value	645,629	596,025
Fair Value, Recurring [Member] \| Warrant [Member]
Investments, fair value	16,685	16,648
Fair Value, Recurring [Member] \| Other Investment [Member]
Investments, fair value	3,664	3,444
Fair Value, Recurring [Member] \| Equity Securities [Member]
Investments, fair value	29,719	31,127
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Investments, fair value	2,580	3,988
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Debt [Member]
Investments, fair value	0	0
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Warrant [Member]
Investments, fair value	0	0
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Other Investment [Member]
Investments, fair value	0	0
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member]
Investments, fair value	2,580	3,988
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Investments, fair value	1,691	1,916
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Debt [Member]
Investments, fair value	0	0
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Warrant [Member]
Investments, fair value	1,691	1,916
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Other Investment [Member]
Investments, fair value	0	0
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member]
Investments, fair value	0	0
Fair Value, Inputs, Level 3 [Member]
Investments, fair value	691,426	641,340
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Investments, fair value	691,426	641,340
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Debt [Member]
Investments, fair value	645,629	596,025
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Warrant [Member]
Investments, fair value	14,994	14,732
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Other Investment [Member]
Investments, fair value	3,664	3,444
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member]
Investments, fair value	$ 27,139	$ 27,139

- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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