Note 5 - Loans Acquired (Detail) - Summary of the changes in the FDIC true-up provision: (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Balance	$ 3,419	$ 3,246
FDIC true-up provision recorded on new acquisitions	328		3,188
Amortization expense	138	131	58
Adjustments related to changes in expected losses	969	42
Balance	$ 4,854	$ 3,419	$ 3,246

Amount of increases to the indemnification asset due to additional estimated losses assumed by the Federal Deposit Insurance Corporation (FDIC), relating to loss sharing agreements with the FDIC.

No definition available.

Name:	us-gaap_FDICIndemnificationAssetAdditionalEstimatedLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration