Note 11 - Other Borrowings and Subordinated Debentures - Long-term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Total other borrowings	$ 522,541	$ 273,159
Subordinated Debentures	67,418	60,397
Total other borrowings and subordinated debentures	589,959	333,556
Federal Home Loan Bank Advances [Member]
FHLB advances, net of discount, due 2017 to 2033, 1.15% to 7.37% secured by residential real estate loans	477,982	225,230
Note Payable Due 10/15/2020 [Member]
Notes payable, due 10/15/2020, 3.85%, fixed rate, unsecured	44,559	47,929
Trust Preferred Securities Due 12/30/2033 Floating Rate of 2.8% Above Three Month LIBOR 1 [Member]
Subordinated Debentures	20,620	20,620
Trust Preferred Securities Due 6/30/2035 [Member]
Subordinated Debentures	9,301	9,225
Trust Preferred Securities Due 9/15/2037 [Member]
Subordinated Debentures	10,246	10,130
Trust Preferred Securities Due 12/3/2033 [Member]
Subordinated Debentures	5,157	5,161
Trust Preferred Securities Due 12/13/2034 [Member]
Subordinated Debentures	5,137	5,105
Trust Preferred Securities, Due 6/6/2037 [Member]
Subordinated Debentures	10,255	10,156
Trust Preferred Securities, Due 12/15/2035 [Member]
Subordinated Debentures	$ 6,702