Note 10 - Fair Values of Financial Instruments - Fair Value Hierarchy of Financial Instruments (Details) - USD ($)		Jun. 30, 2016	Dec. 31, 2015
Fair Value, Inputs, Level 1 [Member] | Reported Value Measurement [Member]
Cash		$ 12,406,000	$ 12,496,000
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Cash		12,406,000	12,496,000
Fair Value, Inputs, Level 1 [Member]
Available-for-sale Securities		0
Fair Value, Inputs, Level 2 [Member] | Reported Value Measurement [Member]
Cash equivalents		94,577,000	77,395,000
Loans held for sale		2,879,000	1,316,000
Bank owned life insurance		66,537,000	58,971,000
Accrued interest receivable		7,268,000	7,836,000
Deposits		2,279,718,000	2,275,382,000
Repurchase agreements		136,690,000	154,771,000
FHLBI advances		178,000,000	68,000,000
Subordinated debentures		44,494,000	55,154,000
Accrued interest payable		1,517	1,479
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Cash equivalents		94,577,000	77,395,000
Loans held for sale		2,879,000	1,316,000
Bank owned life insurance		66,537,000	58,971,000
Accrued interest receivable		7,268,000	7,836,000
Deposits		2,226,310,000	2,208,724,000
Repurchase agreements		136,690,000	154,771,000
FHLBI advances		180,504,000	68,858,000
Subordinated debentures		44,505,000	55,760,000
Accrued interest payable		1,517	1,479
Fair Value, Inputs, Level 3 [Member] | Reported Value Measurement [Member]
Loans, net		2,359,951,000	2,260,730,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Loans, net		2,356,483,000	2,259,710,000
Reported Value Measurement [Member] | Interest Rate Swap [Member]
Interest rate swap	[1]	278,000	253,000
Reported Value Measurement [Member]
Available-for-sale Securities	[1]	323,452,000	346,992,000
FHLBI stock	[2]	8,026,000	7,567,000
Estimate of Fair Value Measurement [Member] | Interest Rate Swap [Member]
Interest rate swap	[1]	278,000	253,000
Estimate of Fair Value Measurement [Member]
Available-for-sale Securities	[1]	323,452,000	346,992,000
FHLBI stock	[2]	8,026,000	7,567,000
Available-for-sale Securities		$ 323,452,000	$ 346,992,000

[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.