Note 6 - Deposits (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Net, Ending Balance	$ 534
Core Deposits [Member] \| Prime Bank [Member]
Finite-Lived Intangible Assets, Net, Ending Balance	$ 44,300

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant