Note 7 - Goodwill and Identifiable Intangible Assets (Detail) - Gross carrying amount of identifiable intangible assets and accumulated amortization (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Gross Carrying Amount	$ 67,108	$ 67,108
Accumulated Amortization	(45,066)	(43,847)
Core Deposits [Member]
Gross Carrying Amount	56,808	56,808
Accumulated Amortization	(36,045)	(34,938)
Mechant Draft Processing [Member]
Gross Carrying Amount	10,300	10,300
Accumulated Amortization	$ (9,021)	$ (8,909)

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16323-109275

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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