FAIR VALUES AND MEASUREMENTS OF FINANCIAL INSTRUMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Values Of Financial Instruments [Line Items]
Cash equivalents and federal funds sold, Carrying Amount	$ 27,151	$ 18,119	$ 22,904	$ 10,723
Securities available for sale, Carrying Amount	11,027us-gaap_AvailableForSaleSecurities	13,941us-gaap_AvailableForSaleSecurities
Other investment securities, Carrying Amount	2,209	2,259
Loans, net of allowance for loan loss, Carrying Amount	275,025	265,625
Accrued interest receivable, Carrying Amount	1,334	1,198
Cash equivalents and federal funds sold, Estimated Fair Value	27,151	18,119
Securities available for sale, Estimated Fair Value	11,027	13,941
Other investment securities, Estimated Fair Value	2,209	2,259
Loans, net of allowance for loan loss, Estimated Fair Value	291,274	268,060
Accrued interest receivable, Estimated Fair Value	1,334cmoh_InterestReceivableFairValue	1,198cmoh_InterestReceivableFairValue
Noninterest-bearing deposits, Carrying Amount	(50,350)cmoh_NoninterestBearingDemandDeposits	(48,935)cmoh_NoninterestBearingDemandDeposits
Interest-bearing deposits, Carrying Amount	(142,022)	(144,733)
Time deposits, Carrying Amount	(106,399)us-gaap_TimeDepositsAtCarryingValue	(87,640)us-gaap_TimeDepositsAtCarryingValue
Federal Funds Purchased, Carring Amount	0us-gaap_FederalFundsPurchased	(1,757)us-gaap_FederalFundsPurchased
FHLB advances, Carrying Amount	(1,692)	(1,808)
Accrued interest payable, Carrying Amount	(51)	(56)
Noninterest-bearing deposits, Estimated Fair Value	(50,350)	(48,935)
Interest-bearing deposits, Estimated Fair value	(142,022)	(144,733)
Time deposits, Estimated Fair Value	(106,283)cmoh_TimeDepositsFairValue	(85,771)cmoh_TimeDepositsFairValue
Federal funds purchased, Estimated Fair Value		(1,757)
FHLB Advances, Estimated Fair Value	(1,374)	(1,477)
Accrued interest payable, Estimated Fair Value	(51)cmoh_InterestPayableFairValue	(56)cmoh_InterestPayableFairValue
Fair Value, Inputs, Level 1 [Member]
Fair Values Of Financial Instruments [Line Items]
Cash equivalents and federal funds sold, Estimated Fair Value	27,151	18,119
Securities available for sale, Estimated Fair Value	0	0
Other investment securities, Estimated Fair Value	0	0
Loans, net of allowance for loan loss, Estimated Fair Value	0	0
Accrued interest receivable, Estimated Fair Value	0	0
Noninterest-bearing deposits, Estimated Fair Value	(50,350)	(48,935)
Interest-bearing deposits, Estimated Fair value	0	0
Time deposits, Estimated Fair Value	0	0
Federal funds purchased, Estimated Fair Value		0
FHLB Advances, Estimated Fair Value	0	0
Accrued interest payable, Estimated Fair Value	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Values Of Financial Instruments [Line Items]
Cash equivalents and federal funds sold, Estimated Fair Value	0	0
Securities available for sale, Estimated Fair Value	11,027	13,941
Other investment securities, Estimated Fair Value	0	0
Loans, net of allowance for loan loss, Estimated Fair Value	0	0
Accrued interest receivable, Estimated Fair Value	0	0
Noninterest-bearing deposits, Estimated Fair Value	0	0
Interest-bearing deposits, Estimated Fair value	(142,022)	(144,733)
Time deposits, Estimated Fair Value	(106,283)	(85,771)
Federal funds purchased, Estimated Fair Value		(1,757)
FHLB Advances, Estimated Fair Value	(1,374)	(1,477)
Accrued interest payable, Estimated Fair Value	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Values Of Financial Instruments [Line Items]
Cash equivalents and federal funds sold, Estimated Fair Value	0	0
Securities available for sale, Estimated Fair Value	0	0
Other investment securities, Estimated Fair Value	2,209	2,259
Loans, net of allowance for loan loss, Estimated Fair Value	291,274	268,060
Accrued interest receivable, Estimated Fair Value	1,334	1,198
Noninterest-bearing deposits, Estimated Fair Value	0	0
Interest-bearing deposits, Estimated Fair value	0	0
Time deposits, Estimated Fair Value	0	0
Federal funds purchased, Estimated Fair Value		0
FHLB Advances, Estimated Fair Value	0	0
Accrued interest payable, Estimated Fair Value	$ (51)	$ (56)

Amount of investment of the balance sheet assertion valued at fair value

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Amount of advances from the Federal Home Loan Bank (FHLB) fair value as of balance sheet date.

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Reflects the fair value of interest bearing demand deposits liabilities.

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The amount of money in demand deposit accounts without bear any interest and that the depositor is entitled to withdraw at any time without prior notice.

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Interest, dividends, rents, ancillary and other revenues earned but not yet received by the entity on its investments.

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Fair value of investments in certain entities that calculate net asset value per share, including, but not limited to, by unit, membership interest, or other ownership interest. Investments include, but are not limited to, investments in certain hedge funds, venture capital funds, private equity funds, real estate partnerships or funds.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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The sum of cash and cash equivalents plus Federal Funds Sold. Cash and cash equivalents consist of short term, highly liquid investments that are readily convertible to known amounts of cash and are so near their maturity that they present negligible risk of changes in value due to changes in interest rates -- usually with an original maturity less than 90 days.

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This item represents a financial instrument (as defined) for which it is not practicable to estimate fair value. Such disclosure may be for an individual financial instrument or a class of financial instruments.

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Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Amount of advances from the Federal Home Loan Bank (FHLB).

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The aggregate of all domestic and foreign interest-bearing deposit liabilities.

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Amount of interest payable on debt, including, but not limited to, trade payables.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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The aggregate amount of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.

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Includes other investments and securities that are not at fair value as of the balance sheet date and those that are not accounted for under the equity method.

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Any certificate of deposit or savings account held by a bank or other financial institution for a short-term specified period of time. Because of their short-term, time deposits are considered highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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