Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Securities available for sale, amortized cost	$ 82,578	$ 78,801
Serial preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Serial preferred stock, authorized (in shares)	500,000	500,000
Serial preferred stock, issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	16,000,000	16,000,000
Common stock, issued shares (in shares)	9,128,662	9,128,662
Treasury stock, shares (in shares)	4,519,222	4,631,124
Collateralized Mortgage Backed Securities [Member]
Securities available for sale, amortized cost	$ 9,145	$ 5,148
Other Debt Obligations [Member]
Securities available for sale, amortized cost	$ 73,433	$ 73,653

Amortized cost of 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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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