Note 8 - Shareholders' Equity - Stock Repurchase Program (Details) - $ / shares	1 Months Ended	3 Months Ended
Mar. 31, 2018	Feb. 28, 2018	Jan. 31, 2018	Mar. 31, 2018
Total number of shares purchased (in shares)	1,878	7,019	8,652	17,549
Average price paid per share (in dollars per share)	$ 8.02	$ 8.26	$ 8.57	$ 8.39
Publicly Announced Stock Repurchase Program [Member]
Total number of shares purchased (in shares)	1,878	7,019	8,652	17,549

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Balance Type:	na
Period Type:	duration