Note 11 - Weighted-average Exercise Price and Weighted-Average Grant Date Fair Value, Options (Details) - $ / shares	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Granted (in dollars per share)	$ 9	$ 11.20	$ 11.43
Weighted-average grant date fair value on the date of grant (in dollars per share)	$ 3.91	$ 4.97	$ 5.42

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration