Note 6 - Loans - Loans Held for Investment, Credit Quality of Loans (Details) - Loans Held for Investment [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Recorded investment	$ 1,210	$ 30,009
Performing Financial Instruments [Member]
Recorded investment	1,210	29,547
Nonperforming Financial Instruments [Member]
Recorded investment		462
Two [Member]
Recorded investment		26,208
Three [Member]
Recorded investment		909
Four [Member]
Recorded investment
Five [Member]
Recorded investment		462
Not Rated [Member]
Recorded investment	1,210	2,430
Internal Ratings [Member]
Recorded investment	1,210	30,009
Baa1 - Baa3 [Member]
Recorded investment
Ba1 - Ba3 [Member]
Recorded investment		7,459
B1 - B3 [Member]
Recorded investment		18,342
Caa1 - Caa3 [Member]
Recorded investment		419
Ca [Member]
Recorded investment		463
Not Rated [Member]
Recorded investment	1,210	3,326
Moodys Credit Rating [Member]
Recorded investment	$ 1,210	$ 30,009