Note 8 - Time Deposits ((Details Textual)) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Banking And Thrift [Abstract]
Total time deposits	$ 225,182	$ 225,582
Time Deposits $250,000 or More	$ 42,362	$ 34,446

Amount of time deposit liabilities, including certificates of deposit.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=50488274&loc=d3e64164-112818

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
-Paragraph D-E

Name:	us-gaap_TimeDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant