Note 7 - Securities Available for Sale - Summary of Securities Available for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Securities available for sale, amortized cost	$ 80,783	$ 81,502
Investment securities available for sale, gross unrealized gains	39	1
Investment securities available for sale, gross unrealized losses	(890)	(1,523)
Securities available for sale	79,932	79,980
Collateralized Mortgage Backed Securities [Member]
Securities available for sale, amortized cost	7,748	8,159
Investment securities available for sale, gross unrealized gains	35	0
Investment securities available for sale, gross unrealized losses	(40)	(136)
Securities available for sale	7,743	8,023
Other Marketable Securities [Member]
Securities available for sale, amortized cost	73,035	73,343
Investment securities available for sale, gross unrealized gains	4	1
Investment securities available for sale, gross unrealized losses	(850)	(1,387)
Securities available for sale	72,189	71,957
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available for sale, amortized cost	3,694	3,886
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(37)	(117)
Securities available for sale	3,657	3,769
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] \| Collateralized Mortgage Obligations [Member]
Securities available for sale, amortized cost	194	199
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(3)	(9)
Securities available for sale	191	190
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available for sale, amortized cost	3,860	4,074
Investment securities available for sale, gross unrealized gains	35	0
Investment securities available for sale, gross unrealized losses	0	(10)
Securities available for sale	3,895	4,064
US Government Agencies Debt Securities [Member] \| Other Marketable Securities [Member]
Securities available for sale, amortized cost	69,973	69,971
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(740)	(1,236)
Securities available for sale	69,233	68,735
US States and Political Subdivisions Debt Securities [Member] \| Other Marketable Securities [Member]
Securities available for sale, amortized cost	2,075	2,378
Investment securities available for sale, gross unrealized gains	4	1
Investment securities available for sale, gross unrealized losses	(4)	(10)
Securities available for sale	2,075	2,369
Corporate Debt Securities [Member] \| Other Marketable Securities [Member]
Securities available for sale, amortized cost	142	173
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(1)	(1)
Securities available for sale	141	172
Preferred Stock [Member] \| Other Marketable Securities [Member]
Securities available for sale, amortized cost	700	700
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(105)	(140)
Securities available for sale	595	560
Equity Securities [Member] \| Other Marketable Securities [Member]
Securities available for sale, amortized cost	145	121
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	0	0
Securities available for sale	$ 145	$ 121

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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