Note 11 - Fair Values of Financial Instruments (Details) - Fair Value Hierarchy of Financial Instruments (USD $)	Mar. 31, 2015		Dec. 31, 2014
Financial assets:
Securities available for sale	$ 413,693,000	[1]	$ 432,912,000	[1]
FHLBI stock	13,699,000	[2]	13,699,000	[2]
FHLBI stock	13,699,000	[2]	13,699,000	[2]
Bank owned life insurance	58,148,000		57,861,000
Financial liabilities:
Deposits	2,279,524,000		2,276,915,000
Repurchase agreements	148,219,000		167,569,000
Accrued interest payable	14,000,000		12,263,000
Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash	13,298,000		13,261,000
Cash	13,298,000		13,261,000
Fair Value, Inputs, Level 2 [Member]
Financial assets:
Cash equivalents	135,492,000		159,477,000
Cash equivalents	135,492,000		159,477,000
Loans held for sale	3,429,000		1,574,000
Loans held for sale	3,429,000		1,574,000
Bank owned life insurance	58,148,000		57,861,000
Bank owned life insurance	58,148,000		57,861,000
Accrued interest receivable	8,748,000		8,033,000
Accrued interest receivable	8,748,000		8,033,000
Financial liabilities:
Deposits	2,279,524,000		2,276,915,000
Deposits	2,253,068,000		2,254,749,000
Repurchase agreements	148,219,000		167,569,000
Repurchase agreements	148,219,000		167,569,000
FHLBI advances	48,011,000		54,022,000
FHLBI advances	48,651,000		54,720,000
Subordinated debentures	54,642,000		54,472,000
Subordinated debentures	54,655,000		54,508,000
Accrued interest payable	1,778,000		1,942,000
Accrued interest payable	1,778,000		1,942,000
Fair Value, Inputs, Level 3 [Member]
Financial assets:
Loans, net	2,096,281,000		2,067,662,000
Loans, net	2,099,094,000		2,062,566,000
Interest Rate Swap [Member]
Financial liabilities:
Interest rate swap	450,000	[1]	253,000	[1]
Interest rate swap	$ 450,000	[1]	$ 253,000	[1]

[1] See Note 12 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.