Accounting Policies Recently Adopted and Pending Accounting Pronouncements	3 Months Ended
Mar. 31, 2016
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Accounting Policies Recently Adopted and Pending Accounting Pronouncements	Note 18 – Accounting Policies Recently Adopted and Pending Accounting Pronouncements ASU 2016-10,“Revenue from Contracts with Customers (Topic 606)-Identifying Performance Obligations and Licensing.” Issued in April 2016, ASU 2016-10 clarifies ASC Topic 606, “Revenue from Contracts with Customers” related to (i) identifying performance obligations; and (ii) the licensing implementation guidance. Since the amendments in ASU 2016-10 affect the guidance in ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”, which is not yet effective, this ASU will become effective when ASU 2014-09 becomes effective. The amendments of ASU 2016-10 are effective for interim and annual periods beginning after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-10 is not expected to have a material impact on Trustmark’s consolidated financial statements. ASU 2016-09,“Compensation-Stock Compensation (Topic 718)-Improvements to Employee Share-Based Payment Accounting.” Issued in March 2016, ASU 2016-09 seeks to reduce complexity in accounting standards by simplifying several aspects of the accounting for share-based payment transactions, including (1) accounting for income taxes; (2) classification of excess tax benefits on the statement of cash flow; (3) forfeitures; (4) minimum statutory tax withholding requirements; (5) classification of employee taxes paid on the statement of cash flows when an employer withholds shares for tax withholding purposes; (6) the practical expedient for estimating the expected term; and (7) intrinsic value. The amendments of ASU 2016-09 are effective for interim and annual periods beginning after December 15, 2016. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-09 is not expected to have a material impact on Trustmark’s consolidated financial statements. ASU 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net).” Issued in March 2016, ASU 2016-08 clarifies certain principal versus agent considerations within the implementation guidance of ASC Topic 606, “Revenue from Contracts with Customers.” Since the amendments in ASU 2016-08 affect the guidance in ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”, which is not yet effective, this ASU will become effective when ASU 2014-09 becomes effective. The amendments of ASU 2016-08 are effective for interim and annual periods beginning after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-08 is not expected to have a material impact on Trustmark’s consolidated financial statements. ASU 2016-07, “Investments - Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” Issued in March 2016, ASU 2016-07 affects all entities that have an investment that becomes qualified for the equity method of accounting as a result of an increase in the level of ownership interest or degree of influence. ASU 2016-07 simplifies the transition to the equity method of accounting by eliminating the retroactive adjustment of the investment when an investment qualifies for use of the equity method, among other things. The amendments of ASU 2016-07 are effective for interim and annual periods beginning after December 15, 2016. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-07 is not expected to have a material impact on Trustmark’s consolidated financial statements. ASU 2016-05,“Derivatives and Hedging (Topic 815) Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships.” Issued in March 2016, ASU 2016-05 clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under ASC Topic 815 does not, in and of itself, require de-designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The amendments of ASU 2016-05 are effective for interim and annual periods beginning after December 15, 2016. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-05 is not expected to have a material impact on Trustmark’s consolidated financial statements. ASU 2016-02, “Leases (Topic 842).” Issued in February 2016, ASU 2016-02 was issued by the FASB to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and by disclosing key information about leasing arrangements. ASU 2016-02 will, among other things, require lessees to recognize a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 does not significantly change lease accounting requirements applicable to lessors; however, the ASU contains some targeted improvements that are intended to align, where necessary, lessor accounting with the lessee accounting model and with the updated revenue recognition guidance issued in 2014. The amendments of ASU 2016-02 are effective for interim and annual periods beginning after December 15, 2018. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-02 is not expected to have a material impact on Trustmark’s consolidated financial statements. ASU 2016-01, “Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (An Amendment of the FASB Accounting Standards Codification).” Issued in January 2016, ASU 2016-01 is intended to enhance the reporting model for financial instruments to provide users of financial statements with improved decision-making information. The amendments of ASU 2016-01 include: (i) requiring equity investments, except those accounted for under the equity method of accounting or those that result in the consolidation of an investee, to be measured at fair value with changes in fair value recognized in net income; (ii) requiring a qualitative assessment to identify impairment of equity investments without readily determinable fair values; and (iii) clarifying that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entity’s other deferred tax assets. The amendments of ASU 2016-01 are effective for interim and annual periods beginning after December 15, 2017. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-01 is not expected to have a material impact on Trustmark’s consolidated financial statements. 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 did 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 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. ASU 2015-14, “Revenue from Contracts with Customers (Topic 606)-Deferral of the Effective Date,” issued in August 2015, defers the effective date of ASU 2014-09 by one year. ASU 2015-14 provides that the amendments of ASU 2014-09 become effective for interim and annual periods beginning after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. 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.

Note 18 – Accounting Policies Recently Adopted and Pending Accounting Pronouncements

ASU 2016-10,“Revenue from Contracts with Customers (Topic 606)-Identifying Performance Obligations and Licensing.” Issued in April 2016, ASU 2016-10 clarifies ASC Topic 606, “Revenue from Contracts with Customers” related to (i) identifying performance obligations; and (ii) the licensing implementation guidance. Since the amendments in ASU 2016-10 affect the guidance in ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”, which is not yet effective, this ASU will become effective when ASU 2014-09 becomes effective. The amendments of ASU 2016-10 are effective for interim and annual periods beginning after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-10 is not expected to have a material impact on Trustmark’s consolidated financial statements.

ASU 2016-09,“Compensation-Stock Compensation (Topic 718)-Improvements to Employee Share-Based Payment Accounting.” Issued in March 2016, ASU 2016-09 seeks to reduce complexity in accounting standards by simplifying several aspects of the accounting for share-based payment transactions, including (1) accounting for income taxes; (2) classification of excess tax benefits on the statement of cash flow; (3) forfeitures; (4) minimum statutory tax withholding requirements; (5) classification of employee taxes paid on the statement of cash flows when an employer withholds shares for tax withholding purposes; (6) the practical expedient for estimating the expected term; and (7) intrinsic value. The amendments of ASU 2016-09 are effective for interim and annual periods beginning after December 15, 2016. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-09 is not expected to have a material impact on Trustmark’s consolidated financial statements.

ASU 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net).” Issued in March 2016, ASU 2016-08 clarifies certain principal versus agent considerations within the implementation guidance of ASC Topic 606, “Revenue from Contracts with Customers.” Since the amendments in ASU 2016-08 affect the guidance in ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”, which is not yet effective, this ASU will become effective when ASU 2014-09 becomes effective. The amendments of ASU 2016-08 are effective for interim and annual periods beginning after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-08 is not expected to have a material impact on Trustmark’s consolidated financial statements.

ASU 2016-07, “Investments - Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” Issued in March 2016, ASU 2016-07 affects all entities that have an investment that becomes qualified for the equity method of accounting as a result of an increase in the level of ownership interest or degree of influence. ASU 2016-07 simplifies the transition to the equity method of accounting by eliminating the retroactive adjustment of the investment when an investment qualifies for use of the equity method, among other things. The amendments of ASU 2016-07 are effective for interim and annual periods beginning after December 15, 2016. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-07 is not expected to have a material impact on Trustmark’s consolidated financial statements.

ASU 2016-05,“Derivatives and Hedging (Topic 815) Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships.” Issued in March 2016, ASU 2016-05 clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under ASC Topic 815 does not, in and of itself, require de-designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The amendments of ASU 2016-05 are effective for interim and annual periods beginning after December 15, 2016. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-05 is not expected to have a material impact on Trustmark’s consolidated financial statements.

ASU 2016-02, “Leases (Topic 842).” Issued in February 2016, ASU 2016-02 was issued by the FASB to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and by disclosing key information about leasing arrangements. ASU 2016-02 will, among other things, require lessees to recognize a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 does not significantly change lease accounting requirements applicable to lessors; however, the ASU contains some targeted improvements that are intended to align, where necessary, lessor accounting with the lessee accounting model and with the updated revenue recognition guidance issued in 2014. The amendments of ASU 2016-02 are effective for interim and annual periods beginning after December 15, 2018. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-02 is not expected to have a material impact on Trustmark’s consolidated financial statements.

ASU 2016-01, “Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (An Amendment of the FASB Accounting Standards Codification).” Issued in January 2016, ASU 2016-01 is intended to enhance the reporting model for financial instruments to provide users of financial statements with improved decision-making information. The amendments of ASU 2016-01 include: (i) requiring equity investments, except those accounted for under the equity method of accounting or those that result in the consolidation of an investee, to be measured at fair value with changes in fair value recognized in net income; (ii) requiring a qualitative assessment to identify impairment of equity investments without readily determinable fair values; and (iii) clarifying that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entity’s other deferred tax assets. The amendments of ASU 2016-01 are effective for interim and annual periods beginning after December 15, 2017. Management is currently evaluating the impact this ASU will have on Trustmark’s consolidated financial statements; however, the adoption of ASU 2016-01 is not expected to have a material impact on Trustmark’s consolidated financial statements.

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 did 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 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. ASU 2015-14, “Revenue from Contracts with Customers (Topic 606)-Deferral of the Effective Date,” issued in August 2015, defers the effective date of ASU 2014-09 by one year. ASU 2015-14 provides that the amendments of ASU 2014-09 become effective for interim and annual periods beginning after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. 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.