Note 5 - Loans Acquired (Details) - Summary of the Covered Impaired Loans Acquired in the Acquisitions During 2012, as of the Dates of Acquisition (USD $) In Thousands, unless otherwise specified	Aug. 31, 2014	Nov. 25, 2013	Dec. 31, 2012
Loans Acquired, Not Covered By FDIC Loss Share [Member] | Purchased Credit Impaired Loans [Member] | Delta Trust [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition	$ 10,726
Non-accretable difference (expected losses and foregone interest)	(7,023)
Cash flows expected to be collected at acquisition	3,703
Accretable yield	(177)
Basis in acquired loans at acquisition	3,526
Loans Acquired, Not Covered By FDIC Loss Share [Member] | Purchased Credit Impaired Loans [Member] | Metropolitan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition		52,830
Non-accretable difference (expected losses and foregone interest)		(21,962)
Cash flows expected to be collected at acquisition		30,868
Accretable yield		(2,516)
Basis in acquired loans at acquisition		28,352
Loans Acquired, Not Covered By FDIC Loss Share [Member] | Delta Trust [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition	316,103
Cash flows expected to be collected at acquisition	316,103
Accretable yield	(7,949)
Basis in acquired loans at acquisition	308,154
Loans Acquired, Not Covered By FDIC Loss Share [Member] | Metropolitan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition		442,009
Cash flows expected to be collected at acquisition		442,009
Accretable yield		(12,989)
Basis in acquired loans at acquisition		429,020
Loans Acquired, Not Covered By FDIC Loss Share [Member] | Truman [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition			99,065
Non-accretable difference (expected losses and foregone interest)			(12,248)
Cash flows expected to be collected at acquisition			86,817
Accretable yield			(13,422)
Basis in acquired loans at acquisition			73,395
Loans Acquired, Not Covered By FDIC Loss Share [Member] | Excel [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition			30,048
Non-accretable difference (expected losses and foregone interest)			(5,170)
Cash flows expected to be collected at acquisition			24,878
Accretable yield			(3,726)
Basis in acquired loans at acquisition			21,152
Loans Acquired, Covered by FDIC Loss Share [Member] | Truman [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition			90,227
Non-accretable difference (expected losses and foregone interest)			(25,308)
Cash flows expected to be collected at acquisition			64,919
Accretable yield			(7,778)
Basis in acquired loans at acquisition			57,141
Loans Acquired, Covered by FDIC Loss Share [Member] | Excel [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition			121,850
Non-accretable difference (expected losses and foregone interest)			(29,258)
Cash flows expected to be collected at acquisition			92,592
Accretable yield			(14,445)
Basis in acquired loans at acquisition			$ 78,147