Summary of significant accounting policies	12 Months Ended
Summary of significant accounting policies	Dec. 31, 2011
Accounting Policies [Abstract]
Summary of significant accounting policies	Summary of significant accounting policies The accounting and reporting policies of City National Bancshares Corporation (the “Corporation” or “CNBC”) and its subsidiaries, City National Bank of New Jersey (the “Bank” or “CNB”) and City National Bank of New Jersey Capital Trust II conform with U.S. generally accepted accounting principles (“GAAP”) and to general practice within the banking industry. In preparing the financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities as of the date of the balance sheet and revenues and expenses for the related periods. Actual results could differ significantly from those estimates. A material estimate that is particularly susceptible to significant change in the near term is the allowance for loan losses. In connection with the determination of this allowance, management generally obtains independent appraisals for significant properties. Judgments related to securities valuation and impairment are also critical because they involve a higher degree of complexity and subjectivity and require estimates and assumptions about highly uncertain matters. Accordingly, it is reasonably possible that the Corporation may be required to record additional provisions for loan losses and other than temporary impairment charges in future periods. Additionally, significant judgment is required to determine the future realization of deferred tax assets and whether a valuation allowance may be required. The following is a summary of the more significant policies and practices. Business City National Bancshares Corporation primarily through its subsidiary City National Bank of New Jersey, offers a broad range of lending, leasing, depository and related financial services to individual consumers, businesses and governmental units through seven full-service offices located in New Jersey, New York City and Long Island, New York. CNB competes with other banking and financial institutions in its primary market communities, including financial institutions with resources substantially greater than its own. Commercial banks, savings banks, savings and loan associations, credit unions, and money market funds actively compete for deposits and loans. Such institutions, as well as consumer finance and insurance companies, may be considered competitors with respect to one or more services they render. CNB offers equipment leasing services through its minority ownership interest in an unconsolidated leasing company. Principles of consolidation The financial statements include the accounts of CNBC and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Cash and cash equivalents For purposes of the presentation of the Statement of Cash Flows, Cash and cash equivalents includes cash and due from banks and federal funds sold. Investment securities held to maturity and investment securities available for sale Investment securities are designated as held to maturity or available for sale at the time of acquisition. Securities that the Corporation has the intent and ability at the time of purchase to hold until maturity are designated as held to maturity. Investment securities held to maturity are stated at cost and adjusted for amortization of premiums and accretion of discount to the earlier of maturity or call date using the level yield method. Securities to be held for indefinite periods of time but not intended to be held until maturity or on a long-term basis are classified as investment securities available for sale. Securities held for indefinite periods of time include securities that the Corporation intends to use as part of its interest rate sensitivity management strategy and that may be sold in response to changes in interest rates, resultant risk and other factors. Investment securities available for sale are reported at fair market value, with unrealized gains and losses, net of deferred tax, reported as a component of accumulated other comprehensive income, which is included in stockholders’ equity. Gains and losses realized from the sales of securities available for sale are determined using the specific identification method. Premiums are amortized and discounts are accreted using the “level yield” method. Investment securities classified as held to maturity or available for sale are evaluated quarterly for other-than-temporary impairment. Other-than-temporary impairment means that the security’s impairment is due to factors that could include its inability to pay interest or dividends, its potential for default, and/or other factors. As a result of the adoption of new authoritative guidance under ASC Topic 320, “Investments—Debt and Equity Securities” on April 1, 2009, when a held to maturity or available for sale debt security is assessed for other-than-temporary impairment, the Corporation has to first consider (a) whether it intends to sell the security, and (b) whether it is more likely than not that the Corporation will be required to sell the security prior to recovery of its amortized cost basis. If one of these circumstances applies to a security, an other-than-temporary impairment loss is recognized in the statement of income equal to the full amount of the decline in fair value below amortized cost. If neither of these circumstances applies to a security, but the Corporation does not expect to recover the entire amortized cost basis, an other-than-temporary impairment loss has occurred that must be separated into two categories: (a) the amount related to credit loss, and (b) the amount related to other factors. In assessing the level of other-than-temporary impairment attributable to credit loss, the Corporation compares the present value of cash flows expected to be collected with the amortized cost basis of the security. The portion of the total other-than-temporary impairment related to credit loss is recognized in earnings, while the amount related to other factors is recognized in other comprehensive income. The total other-than-temporary impairment loss is presented in the statement of income, less the portion recognized in other comprehensive income. When a debt security becomes other-than-temporarily impaired, its amortized cost basis is reduced to reflect the portion of the total impairment related to credit loss. Prior to the adoption of the new authoritative guidance, total other-than-temporary impairment losses (i.e., both credit and non-credit losses) on debt securities were recognized through earnings with an offset to reduce the amortized cost basis of the applicable debt securities by their entire impairment amount. To determine whether a security’s impairment is other-than-temporary, the Corporation considers factors that include the causes of the decline in fair value, such as credit problems, interest rate fluctuations, or market volatility, the severity and duration of the decline, its ability and intent to hold equity security investments until they recover in value (as well as the likelihood of such a recovery in the near term), the intent to sell security investments, or if it is more likely than not that the Corporation will be required to sell such securities before recovery of their individual amortized cost basis less any current-period credit loss. For debt securities, the primary consideration in determining whether impairment is other-than-temporary is whether or not it is probable that current or future contractual cash flows have been or may be impaired. The Bank holds mortgage-backed securities in its investment portfolios, none of which are private-label. Such securities are subject to changes in the prepayment rates of the underlying mortgages, which may affect both the yield and maturity of the securities. The Bank transferred its entire HTM portfolio to AFS in March 2010. This transfer was made in conjunction with a deleveraging program to reduce total asset levels and improve capital ratios. As a result, purchases of securities may not be classified as HTM until the second quarter of 2012. Loans held for sale Loans held for sale include residential mortgage loans originated with the intent to sell. Loans held for sale are carried at the lower of aggregate cost or fair value. Loans Loans are stated at the principal amounts outstanding, net of unearned discount and deferred loan fees, as well as interest received on certain nonaccrual loans. Interest income is accrued as earned, based upon the principal amounts outstanding. Loan origination fees and certain direct loan origination costs, as well as unearned discount, are deferred and recognized over the life of the loan revised for loan prepayments, as an adjustment to the loan’s yield. Recognition of interest on the accrual method is generally discontinued when a loan contractually becomes 90 days or more past due or a reasonable doubt exists as to the collectability of the loan, unless such loans are well-secured and in the process of collection. At the time a loan is placed on a nonaccrual status, previously accrued and uncollected interest is generally reversed against interest income in the current period. Interest on such loans, if appropriate, is recognized as income when payments are received. A loan is returned to an accrual status when it is current as to principal and interest and its future collectability is expected. Generally, this occurs after the loan has been performing for six months. The Corporation has defined the population of impaired loans to be all nonaccrual loans of $100,000 or more. Impaired loans of $100,000 or more are individually assessed to determine that the loan’s carrying value does not exceed the fair value of the underlying collateral or the present value of the loan’s expected future cash flows. Smaller balance homogeneous loans that are collectively evaluated for impairment are specifically excluded from the impaired loan portfolio. Trouble debt restructured (“TDR”) loans are those loans whose terms have been modified because of deterioration of the financial condition of the borrower to provide for a reduction of interest or principal payments, or both. An allowance is established for all TDR loans based on the present value of the respective loan’s future cash flows unless the loan is deemed collateral dependent. The majority of concessions made for TDRs involve lowering the monthly payments on the loans either through a reduction in interest rate below a market rate, an extension of the term of the loan, or a combination of the two methods. They seldom result in the forgiveness of principal or accrued interest. In addition, we attempt to obtain additional collateral or guarantees when modifying such loans. If the borrower demonstrates the ability to perform under the restructured terms, the loan will continue to accrue interest. Nonaccruing restructured loans may be returned to accrual status when there has been a sustained period of repayment performance (generally six consecutive months of payments) and both principal and interest are considered collectible. TDRs are carried at a balance net of any charge-offs required when the modifications to the loan are made and the loan is determined to be a TDR. Allowance for loan losses The allowance for loan losses ("ALLL") is maintained at a level determined adequate to provide for losses inherent in the loan portfolio. The allowance is increased by provisions charged to operations and recoveries of loans previously charged off and reduced by loan charge-offs. Generally, losses on loans are charged against the allowance for loan losses when it is believed that the collection of all or a portion of the principal balance is unlikely and the collateral is not adequate. Certain inherent, but unconfirmed losses are probable within the loan portfolio. The Bank's operations and lending activities are centered in urban communities which are more vulnerable to economic downturns. Unanticipated events, including political, economic and regulatory changes could cause changes in the credit characteristics of the portfolio and result in an unanticipated increase in the allowance. The Bank's current methodology for determining the projected level of losses is based on historical loss rates, current credit grades, specific reserve allocations on loans modified as TDRs and impaired commercial credits above specified thresholds, and other qualitative adjustments. Due to the heavy reliance on realized historical losses and the credit grade rating process, the calculated reserves required under the model may tend to slightly lag the deterioration in the portfolio in a stable or deteriorating credit environment and may tend not to be as responsive when improved conditions have presented themselves. Given these model limitations and market characteristics, the qualitative adjustment factors may be incremental or detrimental to the quantitative model results. An unallocated component to the ALLL is maintained to recognize the imprecision in estimating and measuring loss. Correspondingly, the portion considered unallocated may fluctuate from period to period based on management's evaluation of the factors affecting the assumptions used in calculating the allowance, including historical loss experience and current economic conditions. The allowance is maintained at a level estimated to absorb probable credit losses inherent in the loan portfolio as well as other credit risk related charge-offs. The allowance is based on ongoing evaluations of the probable estimated losses inherent in the loan portfolio. The Bank’s methodology for evaluating the appropriateness of the allowance includes segmentation of the loan portfolio into its various components, tracking the historical levels of classified loans and delinquencies, applying economic outlook factors, assigning specific incremental reserves where necessary, providing specific reserves on impaired loans, and assessing the nature and trend of loan charge-offs. Additionally, the volume of non-performing loans, concentration risks by size, type, and geography, new markets, collateral adequacy and economic conditions are taken into consideration. The allowance established for probable losses on specific loans are based on a regular analysis and evaluation of classified loans. Loans are classified based on an internal credit risk grading process that evaluates, among other things: (i) the obligor’s ability to repay; (ii) the underlying collateral, if any; and (iii) the economic environment and industry in which the borrower operates. Loans with a grade that is below a predetermined grade are adversely classified. Any change in the credit risk grade of performing and/or non-performing loans affects the amount of the related allowance. Once a loan is classified, the loan is analyzed to determine whether the loan is impaired and, if impaired, the need to specifically allocate a portion of the allowance for loan losses to the loan. Specific valuation allowances are determined by analyzing the borrower’s ability to repay amounts owed, collateral deficiencies, the relative risk grade of the loan and economic conditions affecting the borrower’s industry, among other things. Additionally, management individually evaluates nonaccrual loans and all troubled debt restructured loans for impairment based on the underlying anticipated method of payment consisting of either the expected future cash flows from the borrower or the proceeds from the disposition of the related collateral. If payment is expected solely based on the underlying collateral, an appraisal is completed to assess the fair value of the collateral. Collateral dependent impaired loan balances are written down to the current fair value of each loan’s underlying collateral resulting in an immediate charge-off to the allowance, excluding any consideration for personal guarantees that may be pursued in the Bank’s collection process. If repayment is based upon future expected cash flows, the present value of the expected future cash flows discounted at the loan’s original effective interest rate is compared to the carrying value of the loan, and any shortfall is recorded as a specific valuation allowance in the allowance for loan losses. The allowance also contains unallocated reserves to cover inherent losses within a given loan category which have not been otherwise reviewed or measured on an individual basis. This unallocated portion of the allowance reflects management's best estimate of the elements of imprecision and estimation risk inherent in the calculation of the overall allowance. Due to the subjectivity involved in determining the overall allowance, including the unallocated portion, the portion considered unallocated may fluctuate from period to period based on management's evaluation of the factors affecting the assumptions used in calculating the overall allowance, including historical loss experience, current economic conditions, and industry or borrower concentrations. Changes may also occur due to the necessity of maintaining consistent loss coverage ratios for the various loan risk components. Management believes that the allowance for loan losses is adequate. While management uses available information to determine the adequacy of the allowance, future additions may be necessary based on changes in economic conditions or subsequent events unforeseen at the time of evaluation. Additionally, to the extent that actual results differ from forecasts or management's judgment, the ALLL may be greater or less than future charge-offs. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Bank’s allowance for loan losses. Such agencies may require the Bank to increase the allowance based on their judgment of information available to them at the time of their examination. Bank premises and equipment Premises and equipment are stated at cost less accumulated depreciation based upon estimated useful lives of three to 40 years, computed using the straight-line method. Leasehold improvements, carried at cost, net of accumulated depreciation, are generally amortized over the terms of the leases or the estimated useful lives of the assets, whichever are shorter, using the straight-line method. Expenditures for maintenance and repairs are charged to operations as incurred, while major replacements and improvements are capitalized. The net asset values of assets retired or disposed of are removed from the asset accounts and any related gains or losses are included in operations. Other assets Other assets include the Bank’s 35.4% interest in a leasing company. The investment in the unconsolidated investee is carried using the equity method of accounting whereby the carrying value of the investment reflects the Corporation’s initial cost of the investment and the Corporation’s share of the leasing company’s annual net income or loss. Other real estate owned OREO acquired through foreclosure or deed in lieu of foreclosure is carried at the lower of cost or fair value less estimated cost to sell, net of a valuation allowance. When a property is acquired, the excess of the loan balance over the estimated fair value is charged to the allowance for loan losses. Operating results, including any future writedowns of OREO, rental income and operating expenses, are included in “Other expenses.” An allowance for OREO is established through charges to “Other expenses” to maintain properties at the lower of cost or fair value less estimated cost to sell. Core deposit premiums The premium paid for the acquisition of deposits in connection with the purchases of branch offices is amortized on a straight-line basis over a nine-year period, its estimated useful life, and is reviewed at least annually for impairment. If an impairment is found to exist, the carrying value is reduced by a charge to earnings. Amortization totaled $0 in 2011, $566,000 in 2010 and $194,000 in 2009. 2010 included accelerated amortization of $468,000 of core deposit intangibles of two closed branches. As of December 31, 2011, all core deposit premiums have been fully amortized. Long-term debt The Corporation has sold $4 million of trust preferred securities through a wholly-owned statutory business trust. The trust has no independent assets or operations and exists for the sole purpose of issuing trust preferred securities and investing the proceeds thereof in an equivalent amount of junior subordinated debentures issued by the Corporation. The junior subordinate debentures, which are the sole assets of the trusts, are unsecured obligations of the Corporation and are subordinate and junior in right of payment to all present and future senior and subordinated indebtedness and certain other financial obligations of the Corporation. On December 10, 2003, the FASB issued FASB Interpretation No. 46R (“FIN 46R”), which replaced FIN 46. FIN 46R clarifies the applications of Accounting Research Bulletin No. 51 “Consolidated Financial Statements” to certain entities in which equity investors do not have the characteristics of a controlling financial interest or do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support. FIN 46R required the Corporation to de-consolidate its investments in the trusts recorded as long-term debt. Income taxes Federal income taxes are based on currently reported income and expense after the elimination of income which is exempt from Federal income tax. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Such temporary differences include depreciation and the provision for possible loan losses. Where applicable, deferred tax assets are reduced by a valuation allowance for any portions determined not likely to be realized. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A reserve is maintained related to certain tax positions and strategies that management believes contain an element of uncertainty. Management periodically evaluates each of its tax positions and strategies to determine whether the reserve continues to be appropriate. Net loss per common share Basic loss per common share is calculated by dividing net loss less dividends on preferred stock by the weighted average number of common shares outstanding. On a diluted basis, both net loss and common shares outstanding are adjusted to assume the conversion of the convertible subordinate debentures, if determined to be dilutive. Comprehensive income (loss) Other comprehensive income (loss) includes unrealized gains (losses) on securities available for sale (including the non-credit portion of any other-than-temporary impairment charges relating to these securities effective April 1, 2009). Comprehensive income (loss) and its components are included in the consolidated statements of changes in shareholders’ equity. Recent accounting pronouncements Accounting Standards Update (“ASU”) No. 2010-06, “Fair Value Measurements and Disclosures (Topic 820) – Improving Disclosures About Fair Value Measurements,” requires new disclosures and clarifies certain existing disclosure requirements about fair value measurement. Specifically, the update requires an entity to disclose separately the amounts of significant transfers in and out of Level 1 and Level 2 fair value measurements and describe the reasons for such transfers. A reporting entity is required to present separately information about purchases, sales, issuances, and settlements in the reconciliation of fair value measurements using Level 3 inputs. In addition, the update clarifies the following requirements of the existing disclosures: (i) for the purposes of reporting fair value measurements for each class of assets and liabilities, a reporting entity needs to use judgment in determining the appropriate classes of assets; and (ii) a reporting entity is required to include disclosures about the valuation techniques and inputs used to measure fair value for both recurring and nonrecurring fair value measurements. The disclosures related to the gross presentation of purchases, sales, issuances and settlements of assets and liabilities included in Level 3 of the fair value hierarchy became effective on January 1, 2011. The other disclosure requirements and clarifications made by ASU No. 2010-06 became effective on January 1, 2010. ASU No. 2011-02, “Receivables (Topic 310) – A Creditor’s Determination of Whether a Restructuring Is a Troubled Debt Restructuring,” provides clarifying guidance intended to assist creditors in determining whether a modification of the terms of a receivable meets the criteria to be considered a troubled debt restructuring, both for purposes of recording an impairment loss and for disclosure of troubled debt restructurings. In evaluating whether a restructuring constitutes a troubled debt restructuring, a creditor must separately conclude, under the guidance clarified by ASU No. 2011-02, that both of the following exist: (i) the restructuring constitutes a concession to the debtor; and (ii) the debtor is experiencing financial difficulties. ASU No. 2011-02 applies retrospectively to restructurings occurring on or after January 1, 2011 and was effective on July 1, 2011. The adoption of ASU No. 2011-02 is not expected to have a significant impact on the consolidated financial statements. ASU No. 2011-04, “Fair Value Measurements (Topic 820) – Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS,” was issued as a result of the effort to develop common fair value measurement and disclosure requirements in U.S. GAAP and International Financial Reporting Standards (“IFRS”). While ASU No. 2011-04 is largely consistent with existing fair value measurement principles in U.S. GAAP, it expands the existing disclosure requirements for fair value measurements and clarifies the existing guidance or wording changes to align with IFRS No. 13. Many of the requirements for the amendments in ASU No. 2001-04 do not result in a change in the application of the requirements in Topic 820. ASU No. 2011-04 was effective for all interim and annual periods beginning after December 15, 2011. The adoption of ASU No. 2011-04 is not expected to have a significant impact on its consolidated financial statements. ASU No. 2011-05, “Comprehensive Income (Topic 220) – Presentation of Comprehensive Income,” requires an entity to present components of comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. In the two-statement approach, the first statement should present total net income and its components followed consecutively by a second statement that should present total other comprehensive income, the components of other comprehensive income, and the total of comprehensive income. ASU No. 2011-05 must be applied retrospectively and is effective for all interim and annual periods beginning on or after December 15, 2011. The adoption of ASU No. 2011-05 is not expected to have a significant impact on the consolidated financial statements. ASU No. 2011-08, “Intangibles – Goodwill and Other (Topic 350) Testing Goodwill for Impairment,” provides the option of performing a qualitative assessment of whether it is more likely than not that a reporting unit’s fair value is less than its carrying amount, before applying the current two-step goodwill impairment test. If the conclusion is that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the entity would be required to conduct the current two-step goodwill impairment test. Otherwise, the entity would not need to apply the two-step test. ASU No. 2011-28 is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011 with early adoption permitted. The adoption of ASU No. 2011-08 is not expected to have a significant impact on its consolidated financial statements. In April 2010, the FASB issued ASU 2010-18, which states that modifications of loans that are accounted for within a pool under ASC 310-30 do not result in the removal of those loans from the pool even if the modification of those loans would otherwise be considered a troubled debt restructuring. An entity will continue to be required to consider whether the pool of assets in which the loan is included is impaired if expected cash flows for the pool change. The amendments do not affect the accounting for loans under the scope of ASC 310-30 that are not accounted for within pools. Loans accounted for individually under ASC 310-30 continue to be subject to the troubled debt restructuring accounting provisions within ASC 310-40, “Receivables-Troubled Debt Restructurings by Creditors.” The amendments were effective for modifications of loans accounted for within pools under Subtopic 310-30 occurring in the first interim or annual period ending on or after July 15, 2010. The adoption of this pronouncement did not have a material impact on the Corporation's financial condition, results of operations or financial statement disclosures. In July 2010, the FASB issued ASU 2010-20 to provide financial statement users with greater transparency about an entity's allowance for credit losses and the credit quality of its financing receivables. The objective of the ASU is to provide disclosures that assist financial statement users in their evaluation of (1) the nature of an entity's credit risk associated with its financing receivables, (2) how the entity analyzes and assesses that risk in arriving at the allowance for credit losses and (3) the changes in the allowance for credit losses and the reasons for those changes. Disclosures provided to meet the objective above should be provided on a disaggregated basis. The disclosures as of the end of a reporting period were effective for interim and annual reporting periods ending on or after December 15, 2010. The disclosures about activity that occurs during a reporting period were effective for interim and annual reporting periods beginning on or after December 15, 2010. The adoption of this pronouncement did not have a material impact on the Corporation's financial condition or results of operations.

CITY NATIONAL BANCSHARES CORP 10-K