Note 5 - Loans - Loans Collateralizing Asset-Backed Securities Issued, Schedule of Impaired Financing Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Mar. 31, 2019
Impaired loans with an allowance recorded, recorded investment	$ 1,813
Impaired loans with an allowance recorded, unpaid principal balance	1,951
Impaired loans, related allowance	838
Impaired loans with an allowance recorded, average recorded investment	1,817
Impaired loans with an allowance recorded, interest income recognized	119
Impaired loans with no related allowance recorded, recorded investment	0
Impaired loans with no related allowance recorded, unpaid principal balance	0
Impaired loans with no related allowance recorded, average recorded investment	0
Impaired loans with no related allowance recorded, interest income recognized	0
Impaired loans, recorded investment	1,813	$ 0
Impaired loans, unpaid principal balance	1,951
Impaired loans, average recorded investment	1,817
Impaired loans, interest income recognized	$ 119

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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