Note 10 - Fair Values of Financial Instruments (Details) - Fair Value Hierarchy of Financial Instruments - USD ($)		Sep. 30, 2015	Dec. 31, 2014
Financial assets:
Securities available for sale	[1]	$ 367,173,000	$ 432,912,000
FHLBI stock	[2]	7,567,000	13,699,000
FHLBI stock	[2]	7,567,000	13,699,000
Bank owned life insurance		58,680,000	57,861,000
Financial liabilities:
Deposits		2,254,129,000	2,276,915,000
Repurchase agreements		158,149,000	167,569,000
Accrued interest payable		17,296,000	12,263,000
Interest Rate Swap [Member]
Financial liabilities:
Interest rate swap	[1]	533,000	253,000
Interest rate swap	[1]	533,000	253,000
Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash		13,314,000	13,261,000
Cash		13,314,000	13,261,000
Fair Value, Inputs, Level 2 [Member]
Financial assets:
Cash equivalents		90,535,000	159,477,000
Cash equivalents		90,535,000	159,477,000
Loans held for sale		2,057,000	1,574,000
Loans held for sale		2,057,000	1,574,000
Bank owned life insurance		58,680,000	57,861,000
Bank owned life insurance		58,680,000	57,861,000
Accrued interest receivable		8,355,000	8,033,000
Accrued interest receivable		8,355,000	8,033,000
Financial liabilities:
Deposits		2,254,129,000	2,276,915,000
Deposits		2,214,078,000	2,254,749,000
Repurchase agreements		158,149,000	167,569,000
Repurchase agreements		158,149,000	167,569,000
FHLBI advances		68,000,000	54,022,000
FHLBI advances		68,883,000	54,720,000
Subordinated debentures		54,983,000	54,472,000
Subordinated debentures		55,049,000	54,508,000
Accrued interest payable		1,554,000	1,942,000
Accrued interest payable		1,554,000	1,942,000
Fair Value, Inputs, Level 3 [Member]
Financial assets:
Loans, net		2,199,212,000	2,067,662,000
Loans, net		$ 2,200,805,000	$ 2,062,566,000

[1] See Note 11 for a description of the fair value hierarchy as well as a disclosure of levels for classes of financial assets and liabilities.

[2] It is not practical to determine the fair value of FHLBI stock due to transferability restrictions.