Accounting Policies Recently Adopted and Pending Accounting Pronouncements	3 Months Ended
Mar. 31, 2015
Accounting Policies Recently Adopted and Pending Accounting Pronouncements [Abstract]
Accounting Policies Recently Adopted and Pending Accounting Pronouncements	Note 18 – Accounting Policies Recently Adopted and Pending Accounting Pronouncements ASU 2015-02, “Consolidation (Subtopic 810): Amendments to the Consolidation Analysis.” Issued in February 2015, ASU 2015-02 eliminates the indefinite deferral allowed under ASU 2009-17, “Consolidation (Topic 810): Improvements to Financial Reporting by Enterprises Involved with Variable Interest Entities,” for investments in certain investment funds, and significantly changes the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. The changes include, among others, modification of the evaluation of whether limited partnerships and similar legal entities are variable interest entities (VIEs) or voting interest entities and elimination of the presumption that a general partner should consolidate a limited partnership. ASU 2015-02 is expected to result in the deconsolidation of many entities; however, reporting entities will need to reevaluate all previous consolidation conclusions. The amendments of ASU 2015-02 are effective for interim and annual periods beginning after December 15, 2015. The adoption of ASU 2015-02 is not expected to have a material impact on Trustmark's consolidated financial statements. ASU 2014-14, “Receivables – Troubled Debt Restructurings by Creditors (Subtopic 310-40): Classification of Certain Government-Guaranteed Residential Mortgage Loans upon Foreclosure (a consensus of the FASB Emerging Issues Task Force).” Issued in August 2014, ASU 2014-14 requires that a mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if (1) the loan has a government guarantee that is not separable from the loan before foreclosure; (2) at the time of foreclosure, the creditor has the intent to convey the real estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under the claim; and (3) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. ASU 2014-14 also provides that upon foreclosure, the separate other receivable would be measured based on the current amount of the loan balance (principal and interest) expected to be recovered under the guarantee. ASU 2014-14 became effective for Trustmark on January 1, 2015, and was applied using the prospective transition method as described in ASU 2014-14. The adoption of ASU 2014-14 did not have a material impact on Trustmark’s consolidated financial statements. ASU 2014-11, “Transfers and Servicing (Topic 860) – Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures.” Issued in June 2014, ASU 2014-11 changes the accounting for repurchase-to-maturity transactions to secured borrowing accounting, and for repurchase financing arrangements requires separate accounting for a transfer of a financial asset executed contemporaneously with a repurchase agreement with the same counterparty, which will result in secured borrowing accounting for the repurchase agreement. ASU 2014-11 also requires disclosures for certain transactions comprising a transfer of a financial asset accounted for as a sale and an agreement with the same transferee entered into in contemplation of the initial transfer that results in the transferor retaining substantially all of the exposure to the economic return on the transferred financial asset throughout the term of the transaction. ASU 2014-11 requires interim and annual disclosures for repurchase agreements, securities lending transactions and repurchase-to-maturity transactions that are accounted for as secured borrowings, which include a disaggregation of the gross obligation by class of collateral pledged; the remaining contractual tenor of the agreements; and a discussion of the potential risks associated with the agreements and the related collateral pledged, including obligations arising from a decline in the fair value of the collateral pledged and how those risks are managed. The accounting changes and disclosure requirements for certain transactions accounted for as a sale in ASU 2014-11 became effective for Trustmark’s on January 1, 2014 and had no impact on Trustmark’s consolidated financial statements due to Trustmark’s existing policy of accounting for its repurchase agreements as secured borrowings. The disclosures requirements for transactions accounted for as secured borrowings in ASU 2014-11 became effective for Trustmark on April 1, 2015. For Trustmark, the adoption of ASU 2014-11 will be a change in presentation only for the newly required disclosures and will not have a material impact on Trustmark’s consolidated financial statements. ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” Issued in May 2014, ASU 2014-09 will add FASB ASC Topic 606, “Revenue from Contracts with Customers,” and will supersede revenue recognition requirements in FASB ASC Topic 605, “Revenue Recognition,” as well as certain cost guidance in FASB ASC Topic 605-35, “Revenue Recognition – Construction-Type and Production-Type Contracts.” ASU 2014-09 provides a framework for revenue recognition that replaces the existing industry and transaction specific requirements under the existing standards. ASU 2014-09 requires an entity to apply a five-step model to determine when to recognize revenue and at what amount. The model specifies that revenue should be recognized when (or as) an entity transfers control of goods or services to a customer at the amount in which the entity expects to be entitled. Depending on whether certain criteria are met, revenue should be recognized either over time, in a manner that depicts the entity’s performance, or at a point in time, when control of the goods or services are transferred to the customer. ASU 2014-09 provides that an entity should apply the following steps: (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when, or as, the entity satisfies a performance obligation. In addition, the existing requirements for the recognition of a gain or loss on the transfer of non-financial assets that are not in a contract with a customer are amended to be consistent with the guidance on recognition and measurement in ASU 2014-09. The amendments of ASU 2014-09 are effective for interim and annual periods beginning after December 15, 2016, and may be applied either retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying ASU 2014-09 recognized at the date of initial application. If the transition method of application is elected, the entity should also provide the additional disclosures in reporting periods that include the date of initial application of (1) the amount by which each financial statement line item is affected in the current reporting period, as compared to the guidance that was in effect before the change, and (2) an explanation of the reasons for significant changes. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements as well as the most appropriate method of application; however, regardless of the method of application selected, the adoption of ASU 2014-09 is not expected to have a material impact on Trustmark’s consolidated financial statements. ASU 2014-04, “Receivables – Troubled Debt Restructurings by Creditors (Subtopic 310-40): Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure (a consensus of the FASB Emerging Issues Task Force).” Issued in January 2014, ASU 2014-04 clarifies when an “in substance repossession or foreclosure” occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loans, such that all or a portion of the loan should be derecognized and the real estate property recognized. ASU 2014-04 states that a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan, upon either the creditor obtaining legal title to the residential real estate property upon completion of a foreclosure, or the borrower conveying all interest in the residential real estate property to the creditor to satisfy that loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. The amendments of ASU 2014-04 also require interim and annual disclosure of both the amount of foreclosed residential real estate property held by the creditor and the recorded investment in consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure. The amendments of ASU 2014-04 may be applied using either a modified retrospective transition method or a prospective transition method. ASU 2014-04 became effective for Trustmark’s financial statements on January 1, 2015 and was applied using the prospective transition method. For Trustmark, the adoption of ASU 2014-04 resulted in a change in presentation only for the newly required disclosures, which are included in Note 3 – Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI, and had no impact on Trustmark’s consolidated financial statements. ASU 2014-01, “Investments – Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects (a consensus of the FASB Emerging Issues Task Force).” Issued in January 2014, ASU 2014-01 permits reporting entities that invest in qualified affordable housing projects to elect to account for those investments using the “proportional amortization method” if certain conditions are met. Under this method, an entity amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). The decision to apply the proportional amortization method of accounting is an accounting policy decision and should be applied consistently to all qualifying affordable housing project investments. ASU 2014-01 should be applied retrospectively to all periods presented, and became effective for Trustmark’s financial statements on January 1, 2015. Trustmark currently accounts for its tax credit investments utilizing the equity method of accounting and does not have a significant amount of investments in qualified affordable housing projects that qualify for the low income housing tax credit. Trustmark did not elect the proportional amortization method of accounting for its investments in low income housing tax credits; however, management will review any future investments in qualified affordable housing projects to determine if the investments meet the conditions required for using the proportional amortization method of accounting and make a decision regarding the accounting policy. The adoption of ASU 2014-01 had no impact on Trustmark’s consolidated financial statements.

Note 18 – Accounting Policies Recently Adopted and Pending Accounting Pronouncements

ASU 2015-02, “Consolidation (Subtopic 810): Amendments to the Consolidation Analysis.” Issued in February 2015, ASU 2015-02 eliminates the indefinite deferral allowed under ASU 2009-17, “Consolidation (Topic 810): Improvements to Financial Reporting by Enterprises Involved with Variable Interest Entities,” for investments in certain investment funds, and significantly changes the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. The changes include, among others, modification of the evaluation of whether limited partnerships and similar legal entities are variable interest entities (VIEs) or voting interest entities and elimination of the presumption that a general partner should consolidate a limited partnership. ASU 2015-02 is expected to result in the deconsolidation of many entities; however, reporting entities will need to reevaluate all previous consolidation conclusions. The amendments of ASU 2015-02 are effective for interim and annual periods beginning after December 15, 2015. The adoption of ASU 2015-02 is not expected to have a material impact on Trustmark's consolidated financial statements.

ASU 2014-14, “Receivables – Troubled Debt Restructurings by Creditors (Subtopic 310-40): Classification of Certain Government-Guaranteed Residential Mortgage Loans upon Foreclosure (a consensus of the FASB Emerging Issues Task Force).” Issued in August 2014, ASU 2014-14 requires that a mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if (1) the loan has a government guarantee that is not separable from the loan before foreclosure; (2) at the time of foreclosure, the creditor has the intent to convey the real estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under the claim; and (3) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. ASU 2014-14 also provides that upon foreclosure, the separate other receivable would be measured based on the current amount of the loan balance (principal and interest) expected to be recovered under the guarantee. ASU 2014-14 became effective for Trustmark on January 1, 2015, and was applied using the prospective transition method as described in ASU 2014-14. The adoption of ASU 2014-14 did not have a material impact on Trustmark’s consolidated financial statements.

ASU 2014-11, “Transfers and Servicing (Topic 860) – Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures.” Issued in June 2014, ASU 2014-11 changes the accounting for repurchase-to-maturity transactions to secured borrowing accounting, and for repurchase financing arrangements requires separate accounting for a transfer of a financial asset executed contemporaneously with a repurchase agreement with the same counterparty, which will result in secured borrowing accounting for the repurchase agreement. ASU 2014-11 also requires disclosures for certain transactions comprising a transfer of a financial asset accounted for as a sale and an agreement with the same transferee entered into in contemplation of the initial transfer that results in the transferor retaining substantially all of the exposure to the economic return on the transferred financial asset throughout the term of the transaction. ASU 2014-11 requires interim and annual disclosures for repurchase agreements, securities lending transactions and repurchase-to-maturity transactions that are accounted for as secured borrowings, which include a disaggregation of the gross obligation by class of collateral pledged; the remaining contractual tenor of the agreements; and a discussion of the potential risks associated with the agreements and the related collateral pledged, including obligations arising from a decline in the fair value of the collateral pledged and how those risks are managed. The accounting changes and disclosure requirements for certain transactions accounted for as a sale in ASU 2014-11 became effective for Trustmark’s on January 1, 2014 and had no impact on Trustmark’s consolidated financial statements due to Trustmark’s existing policy of accounting for its repurchase agreements as secured borrowings. The disclosures requirements for transactions accounted for as secured borrowings in ASU 2014-11 became effective for Trustmark on April 1, 2015. For Trustmark, the adoption of ASU 2014-11 will be a change in presentation only for the newly required disclosures and will not have a material impact on Trustmark’s consolidated financial statements.

ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” Issued in May 2014, ASU 2014-09 will add FASB ASC Topic 606, “Revenue from Contracts with Customers,” and will supersede revenue recognition requirements in FASB ASC Topic 605, “Revenue Recognition,” as well as certain cost guidance in FASB ASC Topic 605-35, “Revenue Recognition – Construction-Type and Production-Type Contracts.” ASU 2014-09 provides a framework for revenue recognition that replaces the existing industry and transaction specific requirements under the existing standards. ASU 2014-09 requires an entity to apply a five-step model to determine when to recognize revenue and at what amount. The model specifies that revenue should be recognized when (or as) an entity transfers control of goods or services to a customer at the amount in which the entity expects to be entitled. Depending on whether certain criteria are met, revenue should be recognized either over time, in a manner that depicts the entity’s performance, or at a point in time, when control of the goods or services are transferred to the customer. ASU 2014-09 provides that an entity should apply the following steps: (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when, or as, the entity satisfies a performance obligation. In addition, the existing requirements for the recognition of a gain or loss on the transfer of non-financial assets that are not in a contract with a customer are amended to be consistent with the guidance on recognition and measurement in ASU 2014-09. The amendments of ASU 2014-09 are effective for interim and annual periods beginning after December 15, 2016, and may be applied either retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying ASU 2014-09 recognized at the date of initial application. If the transition method of application is elected, the entity should also provide the additional disclosures in reporting periods that include the date of initial application of (1) the amount by which each financial statement line item is affected in the current reporting period, as compared to the guidance that was in effect before the change, and (2) an explanation of the reasons for significant changes. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements as well as the most appropriate method of application; however, regardless of the method of application selected, the adoption of ASU 2014-09 is not expected to have a material impact on Trustmark’s consolidated financial statements.

ASU 2014-04, “Receivables – Troubled Debt Restructurings by Creditors (Subtopic 310-40): Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure (a consensus of the FASB Emerging Issues Task Force).” Issued in January 2014, ASU 2014-04 clarifies when an “in substance repossession or foreclosure” occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loans, such that all or a portion of the loan should be derecognized and the real estate property recognized. ASU 2014-04 states that a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan, upon either the creditor obtaining legal title to the residential real estate property upon completion of a foreclosure, or the borrower conveying all interest in the residential real estate property to the creditor to satisfy that loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. The amendments of ASU 2014-04 also require interim and annual disclosure of both the amount of foreclosed residential real estate property held by the creditor and the recorded investment in consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure. The amendments of ASU 2014-04 may be applied using either a modified retrospective transition method or a prospective transition method. ASU 2014-04 became effective for Trustmark’s financial statements on January 1, 2015 and was applied using the prospective transition method. For Trustmark, the adoption of ASU 2014-04 resulted in a change in presentation only for the newly required disclosures, which are included in Note 3 – Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI, and had no impact on Trustmark’s consolidated financial statements.

ASU 2014-01, “Investments – Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects (a consensus of the FASB Emerging Issues Task Force).” Issued in January 2014, ASU 2014-01 permits reporting entities that invest in qualified affordable housing projects to elect to account for those investments using the “proportional amortization method” if certain conditions are met. Under this method, an entity amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). The decision to apply the proportional amortization method of accounting is an accounting policy decision and should be applied consistently to all qualifying affordable housing project investments. ASU 2014-01 should be applied retrospectively to all periods presented, and became effective for Trustmark’s financial statements on January 1, 2015. Trustmark currently accounts for its tax credit investments utilizing the equity method of accounting and does not have a significant amount of investments in qualified affordable housing projects that qualify for the low income housing tax credit. Trustmark did not elect the proportional amortization method of accounting for its investments in low income housing tax credits; however, management will review any future investments in qualified affordable housing projects to determine if the investments meet the conditions required for using the proportional amortization method of accounting and make a decision regarding the accounting policy. The adoption of ASU 2014-01 had no impact on Trustmark’s consolidated financial statements.