Note 5 - Loans - Loans Held for Investment, Credit Quality of Loans (Details) - Loans Held for Investment [Member] - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Recorded investment		$ 4,853	$ 30,009
Performing Financial Instruments [Member]
Recorded investment		4,853	29,547
Nonperforming Financial Instruments [Member]
Recorded investment			462
Two [Member]
Recorded investment	[1]	1,539	26,208
Three [Member]
Recorded investment	[1]	885	909
Four [Member]
Recorded investment	[1]
Five [Member]
Recorded investment	[1]		462
Not Rated [Member]
Recorded investment	[1]	2,429	2,430
Internal Ratings [Member]
Recorded investment	[1]	4,853	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		4,853	3,326
Moodys Credit Rating [Member]
Recorded investment		$ 4,853	$ 30,009

[1] Loans with an internal rating of 4 or below are reviewed individually to identify loans to be designated for non-accrual status.