Note 5 - Loans Acquired (Details) - Summary of the Non-covered Impaired Loans Acquired in Acquisitions (Loans Acquired, Not Covered By FDIC Loss Share [Member], USD $) In Thousands, unless otherwise specified	Feb. 27, 2015
Purchased Credit Impaired Loans [Member] | Liberty [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition	$ 15,716
Non-accretable difference (expected losses and foregone interest)	(4,978)
Cash flows expected to be collected at acquisition	10,738
Accretable yield	12
Basis in acquired loans at acquisition	10,750
Purchased Credit Impaired Loans [Member] | Community First Bancshares, Inc. [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition	10,143
Non-accretable difference (expected losses and foregone interest)	(3,247)
Cash flows expected to be collected at acquisition	6,896
Accretable yield	104
Basis in acquired loans at acquisition	7,000
Liberty [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition	774,777
Cash flows expected to be collected at acquisition	774,777
Accretable yield	(4,869)
Basis in acquired loans at acquisition	769,908
Community First Bancshares, Inc. [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition	1,153,255
Cash flows expected to be collected at acquisition	1,153,255
Accretable yield	(23,712)
Basis in acquired loans at acquisition	$ 1,129,543