Note 13 - Borrowings - Leverage Ratio (Details)	12 Months Ended
	Dec. 31, 2019
Leverage Ratio1 [Member]
Commitment Fee	0.15%
Leverage Ratio1 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Spread on variable rate	1.25%
Leverage Ratio1 [Member] | Base Rate [Member]
Spread on variable rate	0.25%
Leverage Ratio1 [Member] | Maximum [Member]
Leverage ratio	1
Leverage Ratio 2 [Member]
Commitment Fee	0.20%
Leverage Ratio 2 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Spread on variable rate	1.50%
Leverage Ratio 2 [Member] | Base Rate [Member]
Spread on variable rate	0.50%
Leverage Ratio 2 [Member] | Maximum [Member]
Leverage ratio	1.5
Leverage Ratio 2 [Member] | Minimum [Member]
Leverage ratio	1
Leverage Ratio 3 [Member]
Commitment Fee	0.25%
Leverage Ratio 3 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Spread on variable rate	1.75%
Leverage Ratio 3 [Member] | Base Rate [Member]
Spread on variable rate	0.75%
Leverage Ratio 3 [Member] | Maximum [Member]
Leverage ratio	2
Leverage Ratio 3 [Member] | Minimum [Member]
Leverage ratio	1.5
Leverage Ratio 4 [Member]
Commitment Fee	0.30%
Leverage Ratio 4 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Spread on variable rate	2.00%
Leverage Ratio 4 [Member] | Base Rate [Member]
Spread on variable rate	1.00%
Leverage Ratio 4 [Member] | Maximum [Member]
Leverage ratio	2.5
Leverage Ratio 4 [Member] | Minimum [Member]
Leverage ratio	2
Leverage Ratio 5 [Member]
Commitment Fee	0.35%
Leverage Ratio 5 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Spread on variable rate	2.25%
Leverage Ratio 5 [Member] | Base Rate [Member]
Spread on variable rate	1.25%
Leverage Ratio 5 [Member] | Minimum [Member]
Leverage ratio	2.5