Note 10 - Fair Values of Financial Instruments - Fair Value Hierarchy of Financial Instruments (Details) - USD ($)		Mar. 31, 2017	Dec. 31, 2016
Available-for-sale Securities		$ 332,441,000	$ 328,060,000
Reported Value Measurement [Member]
Available-for-sale Securities	[1]	332,441,000	328,060,000
FHLBI stock	[2]	9,236	8,026
Reported Value Measurement [Member] | Interest Rate Swap [Member]
Interest rate swap	[1]	42,000	84,000
Estimate of Fair Value Measurement [Member]
Available-for-sale Securities	[1]	332,441,000	328,060,000
FHLBI stock	[2]	9,236	8,026
Estimate of Fair Value Measurement [Member] | Interest Rate Swap [Member]
Interest rate swap	[1]	42,000	84,000
Fair Value, Inputs, Level 1 [Member]
Available-for-sale Securities		0
Fair Value, Inputs, Level 1 [Member] | Reported Value Measurement [Member]
Cash		11,279,000	11,493,000
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Cash		11,279,000	11,493,000
Fair Value, Inputs, Level 2 [Member] | Reported Value Measurement [Member]
Cash equivalents		41,697,000	172,103,000
Loans held for sale		1,927	1,035
Bank owned life insurance		66,211,000	67,198,000
Accrued interest receivable		8,542,000	7,714,000
Deposits		2,278,016,000	2,374,985,000
Repurchase agreements		126,679	131,710
FHLBI advances		205,000	175,000
Subordinated debentures		45,006,000	44,835,000
Accrued interest payable		1,465,000	1,592,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Cash equivalents		41,697,000	172,103,000
Loans held for sale		1,927	1,035
Bank owned life insurance		66,211,000	67,198,000
Accrued interest receivable		8,542,000	7,714,000
Deposits		2,181,344,000	2,286,548,000
Repurchase agreements		126,679	131,710
FHLBI advances		204,156	174,734
Subordinated debentures		45,392,000	45,220,000
Accrued interest payable		1,465,000	1,592,000
Fair Value, Inputs, Level 3 [Member] | Reported Value Measurement [Member]
Loans, net		2,421,111,000	2,359,624,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Loans, net		$ 2,410,034,000	$ 2,353,276,000

[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.