Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Centrue Financial Corporation is a bank holding company organized under the laws of the State of Delaware. When we use the terms “Centrue,” the “Company,” “we,” “us,” and “our,” we mean Centrue Financial Corporation, a Delaware corporation, and its consolidated subsidiary. When we use the term the “Bank,” we are referring to our wholly owned banking subsidiary, Centrue Bank. The Company and the Bank provide a full range of banking services to individual and corporate customers located in markets extending from the far western and southern suburbs of the Chicago metropolitan area across Central Illinois and metropolitan St. Louis. These services include demand, time, and savings deposits; business and consumer lending; and mortgage banking. The Company is subject to competition from other financial institutions and nonfinancial institutions providing financial services. Additionally, the Company and the Bank are subject to regulations of certain regulatory agencies and undergo periodic examinations by those regulatory agencies. Basis of presentation The accounting and reporting policies of the Company and its subsidiaries conform to U.S. generally accepted accounting principles (“GAAP”) and general practice within the banking industry. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Material estimates which are particularly susceptible to significant change in the near term relate to the fair value of investment securities and other-than-temporary impairment of securities, the determination of the allowance for loan losses and valuation of other real estate owned. For further information with respect to significant accounting policies followed by the Company in the preparation of its consolidated financial statements, refer to the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. The consolidated financial statements include the accounts of the Company and Centrue Bank. Intercompany balances and transactions have been eliminated in consolidation and certain 2015 amounts have been reclassified to conform to the 2016 presentation. The annualized results of operations during the three and nine months ended September 30, 2016 are not necessarily indicative of the results expected for the year ending December 31, 2016. All financial information in the following tables is in thousands (000s), except share and per share data. In the opinion of management, all normal and recurring adjustments which are necessary to fairly present the results for the interim periods presented have been included. Reverse Stock Split Common shares and per share amounts for all periods shown have been restated to reflect the impact of the 1:30 reverse stock split the Company completed effective May 29, 2015. Capital Event On March 31, 2015, the Company completed the issuance of $76.0 million of new common stock in a private placement offering, $68.2 million of net proceeds after issuance and registration costs of $7.8 million. A total of 6.3 million shares were sold in the offering at a price of $12.00 per share. In conjunction with the stock offering the Company used the proceeds in part to pay $4.9 million in accrued but unpaid interest on its subordinated debentures, redeemed all $32.7 million of Series C Preferred Stock for $19.0 million, settled $10.3 million in notes payable with a financial institution for $8.5 million and made a $36.0 million capital contribution into Centrue Bank. The remaining proceeds have been and will be used for general corporate purposes. Recent Accounting Pronouncements In June 2016 the FASB issued accounting standards update 2016-13 Financial Instruments - Credit Losses, commonly referred to as CECL. The provisions of the update eliminate the probable initial recognition threshold under current GAAP which requires reserves to be based on an incurred loss methodology. Under CECL reserves required for financial assets measured at amortized cost will reflect an organization’s estimate of all expected credit losses over the contractual term of the financial asset and thereby require the use of reasonable and supportable forecasts to estimate future credit losses. Because CECL encompasses all financial assets carried at amortized cost, the requirement that reserves be established based on an organization’s reasonable and supportable estimate of expected credit losses extends to held to maturity (HTM) debt securities. Under the provisions of the update credit losses recognized on available for sale (AFS) debt securities will be presented as an allowance as opposed to a write-down. In addition, CECL will modify the accounting for purchased loans, with credit deterioration since origination, so that reserves are established at the date of acquisition for purchased loans. Under current GAAP a purchased loan’s contractual balance is adjusted to fair value through a credit discount and no reserve is recorded on the purchased loan upon acquisition. Since under CECL reserves will be established for purchased loans at the time of acquisition the accounting for purchased loans is made more comparable to the accounting for originated loans. Finally, increased disclosure requirements under CECL oblige organizations to present the currently required credit quality disclosures disaggregated by the year of origination or vintage. FASB expects that the evaluation of underwriting standards and credit quality trends by financial statement users will be enhanced with the additional vintage disclosures. For public business entities that are SEC filers the amendments of the update are effective beginning January 1, 2020. Management is in the process of evaluating the impact of CECL on the Company’s financial position, results of operations and cash flows as well as its required disclosures. In March 2016, the FASB issued an update (ASU No. 2016-09, Stock Compensation: Improvements to Employee Share-Based Payment Accounting.) The guidance in this update affects any entity that issues share-based payment awards to its employees and is intended to simplify several aspects of the accounting for share-based payment awards including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments in this update are effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted. The adoption of this standard is not expected to have a material effect on the Company's results of operations or financial position. In February 2016, the FASB issued an update (ASU No. 2016-02, Leases) creating FASB Topic 842, Leases. The guidance is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requiring more disclosures related to leasing transactions. The amendments in this update are effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. Early adoption is permitted. Management is currently evaluating the impact on the consolidated financial statements and related disclosures. In January 2016, the FASB issued an update, ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities. The guidance in this update requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. However, an entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The amendments in this update are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Management is currently determining the impact of this new guidance on the consolidated financial statements. In May 2014, the FASB issued an update (ASU No. 2014-09, Revenue from Contracts with Customers) creating FASB Topic 606, Revenue from Contracts with Customers. The guidance in this update affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (for example, insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides steps to follow to achieve the core principle. An entity should disclose sufficient information to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Qualitative and quantitative information is required about contracts with customers, significant judgments and changes in judgments, and assets recognized from the costs to obtain or fulfill a contract. The amendments in this update will become effective for annual periods and interim periods within those annual periods beginning after December 15, 2017. In evaluating this standard, management has determined that the majority of revenue earned by the Company are from revenue streams not included in the scope of this standard and thus no material impact is expected with the adoption of this standard.

Summary of Significant Accounting Policies

Centrue Financial Corporation is a bank holding company organized under the laws of the State of Delaware. When we use the terms “Centrue,” the “Company,” “we,” “us,” and “our,” we mean Centrue Financial Corporation, a Delaware corporation, and its consolidated subsidiary. When we use the term the “Bank,” we are referring to our wholly owned banking subsidiary, Centrue Bank. The Company and the Bank provide a full range of banking services to individual and corporate customers located in markets extending from the far western and southern suburbs of the Chicago metropolitan area across Central Illinois and metropolitan St. Louis. These services include demand, time, and savings deposits; business and consumer lending; and mortgage banking. The Company is subject to competition from other financial institutions and nonfinancial institutions providing financial services. Additionally, the Company and the Bank are subject to regulations of certain regulatory agencies and undergo periodic examinations by those regulatory agencies.

Basis of presentation

The accounting and reporting policies of the Company and its subsidiaries conform to U.S. generally accepted accounting principles (“GAAP”) and general practice within the banking industry. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Material estimates which are particularly susceptible to significant change in the near term relate to the fair value of investment securities and other-than-temporary impairment of securities, the determination of the allowance for loan losses and valuation of other real estate owned.

For further information with respect to significant accounting policies followed by the Company in the preparation of its consolidated financial statements, refer to the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. The consolidated financial statements include the accounts of the Company and Centrue Bank. Intercompany balances and transactions have been eliminated in consolidation and certain 2015 amounts have been reclassified to conform to the 2016 presentation. The annualized results of operations during the three and nine months ended September 30, 2016 are not necessarily indicative of the results expected for the year ending December 31, 2016. All financial information in the following tables is in thousands (000s), except share and per share data. In the opinion of management, all normal and recurring adjustments which are necessary to fairly present the results for the interim periods presented have been included.

Reverse Stock Split

Common shares and per share amounts for all periods shown have been restated to reflect the impact of the 1:30 reverse stock split the Company completed effective May 29, 2015.

Capital Event

On March 31, 2015, the Company completed the issuance of $76.0 million of new common stock in a private placement offering, $68.2 million of net proceeds after issuance and registration costs of $7.8 million. A total of 6.3 million shares were sold in the offering at a price of $12.00 per share. In conjunction with the stock offering the Company used the proceeds in part to pay $4.9 million in accrued but unpaid interest on its subordinated debentures, redeemed all $32.7 million of Series C Preferred Stock for $19.0 million, settled $10.3 million in notes payable with a financial institution for $8.5 million and made a $36.0 million capital contribution into Centrue Bank. The remaining proceeds have been and will be used for general corporate purposes.

Recent Accounting Pronouncements

In June 2016 the FASB issued accounting standards update 2016-13 Financial Instruments - Credit Losses, commonly referred to as CECL. The provisions of the update eliminate the probable initial recognition threshold under current GAAP which requires reserves to be based on an incurred loss methodology. Under CECL reserves required for financial assets measured at amortized cost will reflect an organization’s estimate of all expected credit losses over the contractual term of the financial asset and thereby require the use of reasonable and supportable forecasts to estimate future credit losses. Because CECL encompasses all financial assets carried at amortized cost, the requirement that reserves be established based on an organization’s reasonable and supportable estimate of expected credit losses extends to held to maturity (HTM) debt securities. Under the provisions of the update credit losses recognized on available for sale (AFS) debt securities will be presented as an allowance as opposed to a write-down. In addition, CECL will modify the accounting for purchased loans, with credit deterioration since origination, so that reserves are established at the date of acquisition for purchased loans. Under current GAAP a purchased loan’s contractual balance is adjusted to fair value through a credit discount and no reserve is recorded on the purchased loan upon acquisition. Since under CECL reserves will be established for purchased loans at the time of acquisition the accounting for purchased loans is made more comparable to the accounting for originated loans. Finally, increased disclosure requirements under CECL oblige organizations to present the currently required credit quality disclosures disaggregated by the year of origination or vintage. FASB expects that the evaluation of underwriting standards and credit quality trends by financial statement users will be enhanced with the additional vintage disclosures. For public business entities that are SEC filers the amendments of the update are effective beginning January 1, 2020. Management is in the process of evaluating the impact of CECL on the Company’s financial position, results of operations and cash flows as well as its required disclosures.

In March 2016, the FASB issued an update (ASU No. 2016-09, Stock Compensation: Improvements to Employee Share-Based Payment Accounting.) The guidance in this update affects any entity that issues share-based payment awards to its employees and is intended to simplify several aspects of the accounting for share-based payment awards including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments in this update are effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted. The adoption of this standard is not expected to have a material effect on the Company's results of operations or financial position.

In February 2016, the FASB issued an update (ASU No. 2016-02, Leases) creating FASB Topic 842, Leases. The guidance is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requiring more disclosures related to leasing transactions. The amendments in this update are effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. Early adoption is permitted. Management is currently evaluating the impact on the consolidated financial statements and related disclosures.

In January 2016, the FASB issued an update, ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities. The guidance in this update requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. However, an entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The amendments in this update are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Management is currently determining the impact of this new guidance on the consolidated financial statements.

In May 2014, the FASB issued an update (ASU No. 2014-09, Revenue from Contracts with Customers) creating FASB Topic 606, Revenue from Contracts with Customers. The guidance in this update affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (for example, insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides steps to follow to achieve the core principle. An entity should disclose sufficient information to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Qualitative and quantitative information is required about contracts with customers, significant judgments and changes in judgments, and assets recognized from the costs to obtain or fulfill a contract. The amendments in this update will become effective for annual periods and interim periods within those annual periods beginning after December 15, 2017. In evaluating this standard, management has determined that the majority of revenue earned by the Company are from revenue streams not included in the scope of this standard and thus no material impact is expected with the adoption of this standard.