Note 10 - Fair Values of Financial Instruments (Details) - Fair Value Hierarchy of Financial Instruments - USD ($)		Mar. 31, 2016	Dec. 31, 2015
Financial assets:
Securities available for sale	[1]	$ 343,805,000	$ 346,992,000
FHLBI stock	[2]	7,567,000	7,567,000
FHLBI stock	[2]	7,567,000	7,567,000
Bank owned life insurance		59,248,000	58,971,000
Financial liabilities:
Deposits		2,265,122,000	2,275,382,000
Repurchase agreements		162,312,000	154,771,000
Accrued interest payable		17,745,000	16,445,000
Interest Rate Swap [Member]
Financial liabilities:
Interest rate swap	[1]	274,000	253,000
Interest rate swap	[1]	274,000	253,000
Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash		12,146,000	12,496,000
Cash		12,146,000	12,496,000
Securities available for sale		0
Fair Value, Inputs, Level 2 [Member]
Financial assets:
Cash equivalents		89,035,000	77,395,000
Cash equivalents		89,035,000	77,395,000
Loans held for sale		544,000	1,316,000
Loans held for sale		544,000	1,316,000
Bank owned life insurance		59,248,000	58,971,000
Bank owned life insurance		59,248,000	58,971,000
Accrued interest receivable		8,202,000	7,836,000
Accrued interest receivable		8,202,000	7,836,000
Financial liabilities:
Deposits		2,265,122,000	2,275,382,000
Deposits		2,205,359,000	2,208,724,000
Repurchase agreements		162,312,000	154,771,000
Repurchase agreements		162,312,000	154,771,000
FHLBI advances		98,000,000	68,000,000
FHLBI advances		99,553,000	68,858,000
Subordinated debentures		44,324,000	55,154,000
Subordinated debentures		44,345,000	55,760,000
Accrued interest payable		1,422,000	1,479,000
Accrued interest payable		1,422,000	1,479,000
Fair Value, Inputs, Level 3 [Member]
Financial assets:
Loans, net		2,278,862,000	2,260,730,000
Loans, net		$ 2,275,910,000	$ 2,259,710,000

[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.