Note 11 - Capital Stock (Details) - USD ($)		12 Months Ended
	Feb. 27, 2015	Dec. 31, 2015	Dec. 31, 2013	Mar. 04, 2014	Jul. 23, 2012	Feb. 27, 2009
Note 11 - Capital Stock (Details) [Line Items]
Preferred Stock, Shares Authorized		40,040,000				40,040,000
Preferred Stock, Par or Stated Value Per Share (in Dollars per share)		$ 0.01				$ 0.01
Stock Repurchase Program, Number of Shares Authorized to be Repurchased					850,000
Percent of Oustanding Stock					5.00%
Stock Repurchased During Period, Shares			419,564
Stock Repurchased, Weighted Average Price (in Dollars per share)			$ 25.89
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased			154,136
Shelf Registration Statement Max Capital Allowed to Raise (in Dollars)				$ 300,000,000
Rate Through February 18, 2016 [Member]
Note 11 - Capital Stock (Details) [Line Items]
Preferred Stock, Dividend Rate, Percentage	1.00%
Rate After February 18, 2016 [Member]
Note 11 - Capital Stock (Details) [Line Items]
Preferred Stock, Dividend Rate, Percentage	9.00%
Community First Bancshares Inc [Member]
Note 11 - Capital Stock (Details) [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares		30,852
Community First Bancshares Inc [Member] | Preferred Class A [Member]
Note 11 - Capital Stock (Details) [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	30,852
Maximum [Member]
Note 11 - Capital Stock (Details) [Line Items]
Preferred Stock, Liquidation Preference, Value (in Dollars)						$ 80,000,000