Fair Values of Financial Instruments (Details) (USD $)	3 Months Ended
	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Fair Values of Financial Instruments
FHLBC Redemptions	$ 1,200,000
Financial assets:
Cash and due from banks		30,101,000	33,210,000
Interest bearing deposits with financial institutions		14,096,000	14,450,000
Fair Value		385,486,000	372,191,000
Securities held-to-maturity		259,670,000	256,571,000
FHLBC and Reserve Bank Stock		9,058,000	10,292,000
Bank-owned life insurance		56,807,000	55,410,000
Financial liabilities:
Noninterest bearing deposits		400,447,000	373,389,000
Other short-term borrowings		45,000,000	5,000,000
Junior subordinated debentures		58,378,000	58,378,000
Level 1
Financial assets:
Cash and due from banks		30,101,000	33,210,000
Interest bearing deposits with financial institutions		14,096,000	14,450,000
Fair Value		1,527,000	1,544,000
Financial liabilities:
Noninterest bearing deposits		400,447,000	373,389,000
Junior subordinated debentures		32,441,000	39,777,000
Borrowing interest payable			10,122,000
Level 2
Financial assets:
Fair Value		330,900,000	216,385,000
Securities held-to-maturity		263,266,000	254,328,000
FHLBC and Reserve Bank Stock		9,058,000	10,292,000
Bank-owned life insurance		56,807,000	55,410,000
Loans held for sale		5,072,000	3,822,000
Accrued interest receivable		4,888,000	4,248,000
Financial liabilities:
Interest bearing deposits		1,284,887,000	1,312,476,000
Securities sold under repurchase agreements		21,036,000	22,560,000
Other short-term borrowings		45,000,000	5,000,000
Junior subordinated debentures		22,245,000	27,276,000
Subordinated debenture		39,366,000	39,896,000
Note payable and other borrowings		422,000	423,000
Borrowing interest payable		75,000	6,915,000
Deposit interest payable		467,000	762,000
Level 3
Financial assets:
Fair Value		53,059,000	154,262,000
Loans, net		1,151,223,000	1,072,837,000
Carrying Amount
Financial assets:
Cash and due from banks		30,101,000	33,210,000
Interest bearing deposits with financial institutions		14,096,000	14,450,000
Fair Value		385,486,000	372,191,000
Securities held-to-maturity		259,670,000	256,571,000
FHLBC and Reserve Bank Stock		9,058,000	10,292,000
Bank-owned life insurance		56,807,000	55,410,000
Loans held for sale		5,072,000	3,822,000
Loans, net		1,137,695,000	1,073,975,000
Accrued interest receivable		4,888,000	4,248,000
Financial liabilities:
Noninterest bearing deposits		400,447,000	373,389,000
Interest bearing deposits		1,284,608,000	1,308,739,000
Securities sold under repurchase agreements		21,036,000	22,560,000
Other short-term borrowings		45,000,000	5,000,000
Junior subordinated debentures		58,378,000	58,378,000
Subordinated debenture		45,000,000	45,000,000
Note payable and other borrowings		500,000	500,000
Borrowing interest payable		75,000	17,037,000
Deposit interest payable		467,000	762,000
Total
Financial assets:
Cash and due from banks		30,101,000	33,210,000
Interest bearing deposits with financial institutions		14,096,000	14,450,000
Fair Value		385,486,000	372,191,000
Securities held-to-maturity		263,266,000	254,328,000
FHLBC and Reserve Bank Stock		9,058,000	10,292,000
Bank-owned life insurance		56,807,000	55,410,000
Loans held for sale		5,072,000	3,822,000
Loans, net		1,151,223,000	1,072,837,000
Accrued interest receivable		4,888,000	4,248,000
Financial liabilities:
Noninterest bearing deposits		400,447,000	373,389,000
Interest bearing deposits		1,284,887,000	1,312,476,000
Securities sold under repurchase agreements		21,036,000	22,560,000
Other short-term borrowings		45,000,000	5,000,000
Junior subordinated debentures		54,686,000	67,053,000
Subordinated debenture		39,366,000	39,896,000
Note payable and other borrowings		422,000	423,000
Borrowing interest payable		75,000	17,037,000
Deposit interest payable		$ 467,000	$ 762,000