Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (In Thousands) Nature of Operations: Renasant Corporation (referred to herein as the “Company”) owns and operates Renasant Bank (“Renasant Bank” or the “Bank”) and Renasant Insurance, Inc. (“Renasant Insurance”). The Company offers a diversified range of financial, wealth management and insurance services to its retail and commercial customers through its subsidiaries and full service offices located throughout north and central Mississippi, Tennessee, Georgia, Alabama and north Florida. Basis of Presentation: The accompanying unaudited consolidated financial statements of the Company and its subsidiaries have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Certain prior year amounts have been reclassified to conform to the current year presentation. For further information regarding the Company’s significant accounting policies, refer to the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 filed with the Securities and Exchange Commission on February 28, 2018. Business Combinations: The Company completed its acquisitions of Metropolitan BancGroup, Inc. (“Metropolitan”) and Brand Group Holdings, Inc. (“Brand”) on July 1, 2017 and September 1, 2018, respectively. The acquired institutions’ financial condition and results of operations are included in the Company’s financial condition and results of operations as of the applicable acquisition date. Due to the timing of the respective system conversions and the integration of operations into the Company's existing operations, historical reporting for acquired operations is impracticable, and, therefore disclosure of the amounts of revenue and expenses of the acquired institutions since the acquisition dates is impracticable. In connection with the acquisition of Brand, the Company acquired a portfolio of non-mortgage consumer loans, which is included in the line item “Loans held for sale” on the Company’s Consolidated Balance Sheet as of September 30, 2018. The Company is currently evaluating its long-term plans with respect to this portfolio. In accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 850, “Business Combinations”, these loans were measured at fair value as of the acquisition date. Subsequent to the acquisition date, these loans are carried at the lower of amortized cost or fair value. Use of Estimates: The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates, and such differences may be material. Impact of Recently-Issued Accounting Standards and Pronouncements: In February 2016, FASB issued ASU 2016-02, “Leases (Topic 842)” (“ASU 2016-02”). ASU 2016-02 amends the accounting model and disclosure requirements for leases. The current accounting model for leases distinguishes between capital leases, which are recognized on the balance sheet, and operating leases, which are not. Under the new standard, the lease classifications are defined as finance leases, which are similar to capital leases under current GAAP, and operating leases. Further, a lessee will recognize a lease liability and a right-of-use asset for all leases with a term greater than 12 months on its balance sheet regardless of the lease’s classification, which may significantly increase reported assets and liabilities. The accounting model and disclosure requirements for lessors remains substantially unchanged from current GAAP. ASU 2016-02 is effective for annual and interim periods in fiscal years beginning after December 15, 2018. The Company is currently evaluating the impact ASU 2016-02 will have on its financial position and results of operations, and its financial statement disclosures, and the expected results include the recognition of leased assets and related lease liabilities on the balance sheet, along with leasehold amortization and interest expense recognized in the statements of income. In June 2016, FASB issued ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”). This update will significantly change the way entities recognize impairment on many financial assets by requiring immediate recognition of estimated credit losses expected to occur over the asset’s remaining life. FASB describes this impairment recognition model as the current expected credit loss (“CECL”) model and believes the CECL model will result in more timely recognition of credit losses since it incorporates expected credit losses versus incurred credit losses. The scope of FASB’s CECL model includes loans, held-to-maturity debt instruments, lease receivables, loan commitments and financial guarantees that are not accounted for at fair value. For public companies, this update is effective for interim and annual periods beginning after December 15, 2019. The Company has formed an implementation committee comprised of both accounting and credit employees to guide Renasant Bank through the implementation of ASU 2016-13. Currently, this committee is working with a consulting firm to develop the Company’s CECL model, which includes reviewing the different model requirements and ensuring historical data integrity across all reporting systems. In January 2017, FASB issued ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350)” (“ASU 2017-04”). ASU 2017-04 will amend and simplify current goodwill impairment testing by eliminating certain testing under the current provisions. Under the new guidance, an entity should perform the goodwill impairment test by comparing the fair value of a reporting unit with its carrying value and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. An entity still has the option to perform the quantitative assessment for a reporting unit to determine if a quantitative impairment test is necessary. ASU 2017-04 will be effective for interim and annual periods beginning after December 15, 2019 and is not expected to have a material impact on the Company’s financial statements. In March 2017, FASB issued ASU 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities” (“ASU 2017-08”). ASU 2017-08 requires the amortization period for certain callable debt securities held at a premium to be the earliest call date. ASU 2017-08 will be effective for interim and annual periods beginning after December 15, 2018. The Company is currently evaluating the effect that ASU 2017-08 will have on its financial position and results of operations and its financial statement disclosures. In August 2017, FASB issued ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities” (“ASU 2017-12”). ASU 2017-12 is intended to simplify hedge accounting by eliminating the requirement to separately measure and report hedge effectiveness. ASU 2017-12 also seeks to expand the application of hedge accounting by modifying current requirements to include hedge accounting on partial-term hedges, the hedging of prepayable financial instruments and other strategies. ASU 2017-12 will be effective for interim and annual periods beginning after December 15, 2018. The Company is currently evaluating the effect that ASU 2017-12 will have on its financial position and results of operations and its financial statement disclosures. In August 2018, FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement” (“ASU 2018-13”). ASU 2018-13 is intended to improve the disclosures on fair value measurements by eliminating, amending and adding certain disclosure requirements. These changes are intended to reduce costs for preparers while providing more useful information for financial statement users. ASU 2018-13 will be effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted. The Company is currently evaluating the effect that ASU 2018-13 will have on its financial position and results of operations and its financial statement disclosures.

Summary of Significant Accounting Policies

(In Thousands)

Nature of Operations: Renasant Corporation (referred to herein as the “Company”) owns and operates Renasant Bank (“Renasant Bank” or the “Bank”) and Renasant Insurance, Inc. (“Renasant Insurance”). The Company offers a diversified range of financial, wealth management and insurance services to its retail and commercial customers through its subsidiaries and full service offices located throughout north and central Mississippi, Tennessee, Georgia, Alabama and north Florida.

Basis of Presentation: The accompanying unaudited consolidated financial statements of the Company and its subsidiaries have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Certain prior year amounts have been reclassified to conform to the current year presentation. For further information regarding the Company’s significant accounting policies, refer to the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 filed with the Securities and Exchange Commission on February 28, 2018.

Business Combinations: The Company completed its acquisitions of Metropolitan BancGroup, Inc. (“Metropolitan”) and Brand Group Holdings, Inc. (“Brand”) on July 1, 2017 and September 1, 2018, respectively. The acquired institutions’ financial condition and results of operations are included in the Company’s financial condition and results of operations as of the applicable acquisition date. Due to the timing of the respective system conversions and the integration of operations into the Company's existing operations, historical reporting for acquired operations is impracticable, and, therefore disclosure of the amounts of revenue and expenses of the acquired institutions since the acquisition dates is impracticable.

In connection with the acquisition of Brand, the Company acquired a portfolio of non-mortgage consumer loans, which is included in the line item “Loans held for sale” on the Company’s Consolidated Balance Sheet as of September 30, 2018. The Company is currently evaluating its long-term plans with respect to this portfolio. In accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 850, “Business Combinations”, these loans were measured at fair value as of the acquisition date. Subsequent to the acquisition date, these loans are carried at the lower of amortized cost or fair value.

Use of Estimates: The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates, and such differences may be material.

Impact of Recently-Issued Accounting Standards and Pronouncements:

In February 2016, FASB issued ASU 2016-02, “Leases (Topic 842)” (“ASU 2016-02”). ASU 2016-02 amends the accounting model and disclosure requirements for leases. The current accounting model for leases distinguishes between capital leases, which are recognized on the balance sheet, and operating leases, which are not. Under the new standard, the lease classifications are defined as finance leases, which are similar to capital leases under current GAAP, and operating leases. Further, a lessee will recognize a lease liability and a right-of-use asset for all leases with a term greater than 12 months on its balance sheet regardless of the lease’s classification, which may significantly increase reported assets and liabilities. The accounting model and disclosure requirements for lessors remains substantially unchanged from current GAAP. ASU 2016-02 is effective for annual and interim periods in fiscal years beginning after December 15, 2018. The Company is currently evaluating the impact ASU 2016-02 will have on its financial position and results of operations, and its financial statement disclosures, and the expected results include the recognition of leased assets and related lease liabilities on the balance sheet, along with leasehold amortization and interest expense recognized in the statements of income.

In June 2016, FASB issued ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”). This update will significantly change the way entities recognize impairment on many financial assets by requiring immediate recognition of estimated credit losses expected to occur over the asset’s remaining life. FASB describes this impairment recognition model as the current expected credit loss (“CECL”) model and believes the CECL model will result in more timely recognition of credit losses since it incorporates expected credit losses versus incurred credit losses. The scope of FASB’s CECL model includes loans, held-to-maturity debt instruments, lease receivables, loan commitments and financial guarantees that are not accounted for at fair value. For public companies, this update is effective for interim and annual periods beginning after December 15, 2019. The Company has formed an implementation committee comprised of both accounting and credit employees to guide Renasant Bank through the implementation of ASU 2016-13. Currently, this committee is working with a consulting firm to develop the Company’s CECL model, which includes reviewing the different model requirements and ensuring historical data integrity across all reporting systems.

In January 2017, FASB issued ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350)” (“ASU 2017-04”). ASU 2017-04 will amend and simplify current goodwill impairment testing by eliminating certain testing under the current provisions. Under the new guidance, an entity should perform the goodwill impairment test by comparing the fair value of a reporting unit with its carrying value and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. An entity still has the option to perform the quantitative assessment for a reporting unit to determine if a quantitative impairment test is necessary. ASU 2017-04 will be effective for interim and annual periods beginning after December 15, 2019 and is not expected to have a material impact on the Company’s financial statements.

In March 2017, FASB issued ASU 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities” (“ASU 2017-08”). ASU 2017-08 requires the amortization period for certain callable debt securities held at a premium to be the earliest call date. ASU 2017-08 will be effective for interim and annual periods beginning after December 15, 2018. The Company is currently evaluating the effect that ASU 2017-08 will have on its financial position and results of operations and its financial statement disclosures.

In August 2017, FASB issued ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities” (“ASU 2017-12”). ASU 2017-12 is intended to simplify hedge accounting by eliminating the requirement to separately measure and report hedge effectiveness. ASU 2017-12 also seeks to expand the application of hedge accounting by modifying current requirements to include hedge accounting on partial-term hedges, the hedging of prepayable financial instruments and other strategies. ASU 2017-12 will be effective for interim and annual periods beginning after December 15, 2018. The Company is currently evaluating the effect that ASU 2017-12 will have on its financial position and results of operations and its financial statement disclosures.

In August 2018, FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement” (“ASU 2018-13”). ASU 2018-13 is intended to improve the disclosures on fair value measurements by eliminating, amending and adding certain disclosure requirements. These changes are intended to reduce costs for preparers while providing more useful information for financial statement users. ASU 2018-13 will be effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted. The Company is currently evaluating the effect that ASU 2018-13 will have on its financial position and results of operations and its financial statement disclosures.