Trustmark (TRMK) 10-Q 6 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Cover [Abstract]
Entity Registrant Name	Trustmark Corp
Entity Central Index Key	0000036146
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		63,422,439
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Trading Symbol	TRMK
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, no par value
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity File Number	000-03683
Entity Incorporation, State or Country Code	MS
Entity Tax Identification Number	64-0471500
Entity Address, Address Line One	248 East Capitol Street
Entity Address, City or Town	Jackson
Entity Address, State or Province	MS
Entity Address, Postal Zip Code	39201
City Area Code	601
Local Phone Number	208-5111
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Assets
Cash and due from banks		$ 1,026,640	$ 358,916
Securities available for sale, at fair value (amortized cost: $1,839,578; allowance for credit losses: $0)		1,884,153	1,602,404
Securities held to maturity, net of allowance for credit losses of $0 (fair value: $690,561-2020; $746,202-2019)		660,048	738,099
Paycheck Protection Program (PPP) loans		939,783
Loans held for sale (LHFS)		355,089	226,347
Loans held for investment (LHFI)	[1]	9,659,806	9,335,628
Less allowance for credit losses (ACL), LHFI	[1]	119,188	84,277
Net LHFI		9,540,618	9,251,351
Acquired loans	[1]		72,601
Less allowance for loan losses, acquired loans	[1]		815
Net acquired loans			71,786
Net LHFI and acquired loans		9,540,618	9,323,137
Premises and equipment, net		190,567	189,791
Mortgage servicing rights		57,811	79,394
Goodwill		385,270	379,627
Identifiable intangible assets, net		8,895	7,343
Other real estate		18,276	29,248
Operating lease right-of-use assets		29,819	31,182
Other assets		595,110	532,389
Total Assets		15,692,079	13,497,877
Deposits:
Noninterest-bearing		3,880,540	2,891,215
Interest-bearing		9,624,933	8,354,342
Total deposits		13,505,473	11,245,557
Federal funds purchased and securities sold under repurchase agreements		70,255	256,020
Other borrowings		152,860	85,396
ACL on off-balance sheet credit exposures	[1]	42,663	0
Junior subordinated debt securities		61,856	61,856
Operating lease liabilities		31,076	32,354
Other liabilities		153,952	155,992
Total Liabilities		14,018,135	11,837,175
Shareholders' Equity
Common stock, no par value: Authorized: 250,000,000 shares Issued and outstanding: 63,422,439 shares - 2020; 64,200,111 shares - 2019		13,214	13,376
Capital surplus		230,613	256,400
Retained earnings		1,419,552	1,414,526
Accumulated other comprehensive income (loss), net of tax		10,565	(23,600)
Total Shareholders' Equity		1,673,944	1,660,702
Total Liabilities and Shareholders' Equity		$ 15,692,079	$ 13,497,877
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets
Securities available-for-sale, amortized cost	$ 1,839,578	$ 1,600,984
Securities available-for-sale, allowance for credit Losses	0	0
Securities held to maturity, net of allowance for credit losses	0	0
Securities held to maturity, fair value	$ 690,561	$ 746,202
Shareholders' Equity
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, authorized (in shares)	250,000,000	250,000,000
Common stock, issued (in shares)	63,422,439	64,200,111
Common stock, outstanding (in shares)	63,422,439	64,200,111

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest Income
Interest and fees on LHFS & LHFI		$ 96,359	$ 111,740	$ 202,704	$ 218,535
Interest and fees on PPP loans		5,044		5,044
Interest and fees on acquired loans	[1]		2,010		3,926
Interest on securities:
Taxable		12,762	13,916	25,710	28,581
Tax exempt		249	436	610	946
Interest on federal funds sold and securities purchased under reverse repurchase agreements			214		216
Other interest income		239	1,820	979	3,423
Total Interest Income		114,653	130,136	235,047	255,627
Interest Expense
Interest on deposits		8,730	21,500	23,687	41,070
Interest on federal funds purchased and securities sold under repurchase agreements		42	81	667	369
Other interest expense		881	831	1,741	1,656
Total Interest Expense		9,653	22,412	26,095	43,095
Net Interest Income		105,000	107,724	208,952	212,532
Provision for credit losses (PCL)	[1]	18,185	2,486	38,766	4,097
Provision for loan losses, acquired loans	[1]		106		184
Net Interest Income After PCL		86,815	105,132	170,186	208,251
Noninterest Income
Service charges on deposit accounts		6,397	10,379	16,429	20,644
Bank card and other fees		7,717	8,004	13,072	15,195
Mortgage banking, net		33,745	10,295	61,228	13,737
Insurance commissions		11,868	11,089	23,418	21,960
Wealth management		7,571	7,742	16,108	15,225
Other, net		2,213	2,130	4,520	4,369
Total Noninterest Income		69,511	49,639	134,775	91,130
Noninterest Expense
Salaries and employee benefits		66,107	61,949	135,255	122,903
Services and fees		20,567	18,009	40,497	34,977
Net occupancy - premises		6,587	6,403	12,873	12,857
Equipment expense		5,620	5,958	11,236	11,882
Other real estate expense, net		271	132	1,565	1,884
Credit loss expense related to off-balance sheet credit exposures	[1]	6,242		13,025
Other expense		13,265	13,650	28,018	27,619
Total Noninterest Expense		118,659	106,101	242,469	212,122
Income Before Income Taxes		37,667	48,670	62,492	87,259
Income taxes		5,517	6,530	8,124	11,780
Net Income		$ 32,150	$ 42,140	$ 54,368	$ 75,479
Earnings Per Share
Basic		$ 0.51	$ 0.65	$ 0.86	$ 1.16
Diluted		$ 0.51	$ 0.65	$ 0.85	$ 1.16
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income per consolidated statements of income	$ 32,150	$ 42,140	$ 54,368	$ 75,479
Net unrealized gains (losses) on available for sale securities and transferred securities:
Net unrealized holding gains (losses) arising during the period	1,986	15,059	32,366	29,177
Change in net unrealized holding loss on securities transferred to held to maturity	583	942	1,229	1,502
Reclassification adjustments for changes realized in net income:
Net change in prior service costs	28	47	56	94
Recognized net loss due to lump sum settlement	30	47	30	71
Change in net actuarial loss	240	186	484	376
Derivatives:
Change in the accumulated gain (loss) on effective cash flow hedge derivatives	0	(76)	0	(123)
Reclassification adjustment for (gain) loss realized in net income	0	(106)	0	(234)
Other comprehensive income (loss), net of tax	2,867	16,099	34,165	30,863
Comprehensive income	$ 35,017	$ 58,239	$ 88,533	$ 106,342

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2018	$ 1,591,453	$ 13,717	$ 309,545	$ 1,323,870	$ (55,679)
Balance (in shares) at Dec. 31, 2018		65,834,395
Net income per consolidated statements of income	33,339			33,339
Other comprehensive income (loss), net of tax	14,764				14,764
Common stock dividends paid ($0.23 per share)	(15,033)			(15,033)
Shares withheld to pay taxes, long-term incentive plan	(1,604)	$ 25	(1,629)
Shares withheld to pay taxes, long-term incentive plan (in shares)		123,821
Repurchase and retirement of common stock	(36,893)	$ (243)	(36,650)
Repurchase and retirement of common stock (in shares)		(1,168,273)
Compensation expense, long-term incentive plan	1,002		1,002
Balance at Mar. 31, 2019	1,587,028	$ 13,499	272,268	1,342,176	(40,915)
Balance (in shares) at Mar. 31, 2019		64,789,943
Balance at Dec. 31, 2018	1,591,453	$ 13,717	309,545	1,323,870	(55,679)
Balance (in shares) at Dec. 31, 2018		65,834,395
Net income per consolidated statements of income	75,479
Other comprehensive income (loss), net of tax	30,863
Compensation expense, long-term incentive plan	2,281
Balance at Jun. 30, 2019	1,618,550	$ 13,418	260,619	1,369,329	(24,816)
Balance (in shares) at Jun. 30, 2019		64,398,846
Balance at Mar. 31, 2019	1,587,028	$ 13,499	272,268	1,342,176	(40,915)
Balance (in shares) at Mar. 31, 2019		64,789,943
Net income per consolidated statements of income	42,140			42,140
Other comprehensive income (loss), net of tax	16,099				16,099
Common stock dividends paid ($0.23 per share)	(14,987)			(14,987)
Shares withheld to pay taxes, long-term incentive plan	(1)	$ 2	(3)
Shares withheld to pay taxes, long-term incentive plan (in shares)		7,087
Repurchase and retirement of common stock	(13,008)	$ (83)	(12,925)
Repurchase and retirement of common stock (in shares)		(398,184)
Compensation expense, long-term incentive plan	1,279		1,279
Balance at Jun. 30, 2019	1,618,550	$ 13,418	260,619	1,369,329	(24,816)
Balance (in shares) at Jun. 30, 2019		64,398,846
Balance at Dec. 31, 2019	$ 1,660,702	$ 13,376	256,400	1,414,526	(23,600)
Balance (in shares) at Dec. 31, 2019	64,200,111	64,200,111
FASB ASU 2016-13 adoption adjustment	$ (19,949)			(19,949)
Net income per consolidated statements of income	22,218			22,218
Other comprehensive income (loss), net of tax	31,298				31,298
Common stock dividends paid ($0.23 per share)	(14,706)			(14,706)
Shares withheld to pay taxes, long-term incentive plan	(1,020)	$ 17	(1,037)
Shares withheld to pay taxes, long-term incentive plan (in shares)		83,759
Repurchase and retirement of common stock	(27,538)	$ (184)	(27,354)
Repurchase and retirement of common stock (in shares)		(886,958)
Compensation expense, long-term incentive plan	1,394		1,394
Balance at Mar. 31, 2020	1,652,399	$ 13,209	229,403	1,402,089	7,698
Balance (in shares) at Mar. 31, 2020		63,396,912
Balance at Dec. 31, 2019	$ 1,660,702	$ 13,376	256,400	1,414,526	(23,600)
Balance (in shares) at Dec. 31, 2019	64,200,111	64,200,111
Net income per consolidated statements of income	$ 54,368
Other comprehensive income (loss), net of tax	34,165
Compensation expense, long-term incentive plan	2,668
Balance at Jun. 30, 2020	$ 1,673,944	$ 13,214	230,613	1,419,552	10,565
Balance (in shares) at Jun. 30, 2020	63,422,439	63,422,439
Balance at Mar. 31, 2020	$ 1,652,399	$ 13,209	229,403	1,402,089	7,698
Balance (in shares) at Mar. 31, 2020		63,396,912
Net income per consolidated statements of income	32,150			32,150
Other comprehensive income (loss), net of tax	2,867				2,867
Common stock dividends paid ($0.23 per share)	(14,687)			(14,687)
Shares withheld to pay taxes, long-term incentive plan	(59)	$ 5	(64)
Shares withheld to pay taxes, long-term incentive plan (in shares)		25,527
Compensation expense, long-term incentive plan	1,274		1,274
Balance at Jun. 30, 2020	$ 1,673,944	$ 13,214	$ 230,613	$ 1,419,552	$ 10,565
Balance (in shares) at Jun. 30, 2020	63,422,439	63,422,439

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019
Statement Of Stockholders Equity [Abstract]
Cash dividends paid on common stock (in dollars per share)	$ 0.23	$ 0.23	$ 0.23	$ 0.23

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019
Operating Activities
Net income per consolidated statements of income		$ 54,368	$ 75,479
Adjustments to reconcile net income to net cash provided by operating activities:
Credit loss expense, net	[1]	51,791	4,281
Depreciation and amortization		19,656	19,123
Net amortization of securities		4,666	3,918
Gains on sales of loans, net		(30,361)	(9,098)
Compensation expense, long-term incentive plan		2,668	2,281
Deferred income tax provision		(19,500)	(4,400)
Proceeds from sales of loans held for sale		1,133,259	497,187
Purchases and originations of loans held for sale		(1,167,299)	(586,444)
Originations of mortgage servicing rights		(12,396)	(6,075)
Earnings on bank-owned life insurance		(2,544)	(2,715)
Net change in other assets		(45,712)	(14,988)
Net change in other liabilities		(1,491)	(417)
Other operating activities, net		28,447	18,498
Net cash from operating activities		15,552	(3,370)
Investing Activities
Proceeds from maturities, prepayments and calls of securities held to maturity		79,114	85,007
Proceeds from maturities, prepayments and calls of securities available for sale		249,383	213,479
Purchases of securities available for sale		(492,067)	(9,303)
Net proceeds from bank-owned life insurance		592	2,013
Net change in federal funds sold and securities purchased under reverse repurchase agreements		0	(74,669)
Net change in member bank stock		361	(173)
Net change in LHFI and PPP loans		(1,193,397)	(266,949)
Purchases of premises and equipment		(8,638)	(8,372)
Proceeds from sales of premises and equipment		3	2,373
Proceeds from sales of other real estate		10,279	4,105
Purchases of software		(3,179)	(6,861)
Investments in tax credit and other partnerships		(1,612)	(3,426)
Purchase of insurance book of business		(3,097)	(81)
Net cash used in business acquisition		(4,834)	0
Net cash from investing activities		(1,367,092)	(62,857)
Financing Activities
Net change in deposits		2,259,916	202,218
Net change in federal funds purchased and securities sold under repurchase agreements		(185,765)	1,329
Net change in short-term borrowings		4,062	127
Payments on long-term FHLB advances		(34)	(34)
Payments under finance lease obligations		(905)	(1,035)
Common stock dividends		(29,393)	(30,020)
Repurchase and retirement of common stock		(27,538)	(49,901)
Shares withheld to pay taxes, long-term incentive plan		(1,079)	(1,605)
Net cash from financing activities		2,019,264	121,079
Net change in cash and cash equivalents		667,724	54,852
Cash and cash equivalents at beginning of period		358,916	349,561
Cash and cash equivalents at end of period		$ 1,026,640	$ 404,413
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Business, Basis of Financial St

Business, Basis of Financial Statement Presentation and Principles of Consolidation	6 Months Ended
	Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business, Basis of Financial Statement Presentation and Principles of Consolidation	Note 1 – Business, Basis of Financial Statement Presentation and Principles of Consolidation Trustmark Corporation (Trustmark) is a bank holding company headquartered in Jackson, Mississippi. Through its subsidiaries, Trustmark operates as a financial services organization providing banking and financial solutions to corporate institutions and individual customers through 187 offices at June 30, 2020 in Alabama, Florida, Mississippi, Tennessee and Texas. The consolidated financial statements include the accounts of Trustmark and all other entities in which Trustmark has a controlling financial interest. All significant intercompany accounts and transactions have been eliminated in consolidation. Certain reclassifications have been made to prior period amounts to conform to the current period presentation. The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (GAAP) for interim financial information and 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 and should be read in conjunction with the consolidated financial statements, and notes thereto, included in Trustmark’s Annual Report on Form 10-K for its fiscal year ended December 31, 2019 (2019 Annual Report). Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year or any future period. In the opinion of Management, all adjustments (consisting of normal recurring accruals) considered necessary for the fair presentation of these consolidated financial statements have been included. The preparation of financial statements in conformity with these accounting principles requires Management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and income and expense during the reporting periods and the related disclosures. Although Management’s estimates contemplate current conditions and how they are expected to change in the future, it is reasonably possible that in 2020 actual conditions could vary from those anticipated, which could affect Trustmark’s financial condition and results of operations. Actual results could differ from those estimates. Coronavirus 2019 (COVID-19) Pandemic On March 11, 2020, the World Health Organization declared COVID-19, the disease caused by the novel coronavirus, a pandemic as a result of the global spread of the coronavirus illness. The COVID-19 pandemic has adversely affected, and may continue to adversely affect economic activity globally, nationally and locally. In response to the outbreak, federal and state authorities in the United States introduced various measures to try to limit or slow the spread of the virus, including travel restrictions, nonessential business closures, stay-at-home orders, and strict social distancing. The full impact of the COVID-19 pandemic is unknown and rapidly evolving. It has caused substantial disruption in international and U.S. economies, markets, and employment. The COVID-19 pandemic may have a significant adverse impact on certain industries Trustmark serves, including restaurants and food services, hotels, retail and energy. Because of the significant uncertainties related to the ultimate duration of the COVID-19 pandemic and its potential effects on customers and prospects, and on the national and local economy as a whole, there can be no assurances as to how the crisis may ultimately affect Trustmark’s loan portfolio. It is unknown how long the adverse conditions associated with the COVID-19 pandemic will last and what the complete financial effect will be to Trustmark. It is reasonably possible that estimates made in the financial statements could be materially and adversely impacted in the near term as a result of these conditions, including expected credit losses on loans and off-balance sheet credit exposures. See Note 3 – LHFI and Allowance for Credit Losses, LHFI for information regarding the impact of COVID-19 on Trustmark’s loan portfolio. Paycheck Protection Program (PPP) Loans On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (the CARES Act), a stimulus package intended to provide relief to businesses and consumers in the United States struggling as a result of the pandemic, was signed into law. A provision in the CARES Act included a $349 billion fund for the creation of the Paycheck Protection Program (PPP) through the Small Business Administration (SBA) and Treasury Department. The PPP is intended to provide loans to small businesses to pay their employees, rent, mortgage interest and utilities. PPP loans are forgivable, in whole or in part, if the proceeds are used for payroll and other permitted purposes in accordance with the requirements of the PPP. If not forgiven, in whole or in part, these loans carry a fixed rate of 1.00% per annum with payments deferred for the first six months of the loan. Originally, the loans carried a term of two years under SBA rules implemented by the CARES Act, but a June 5, 2020 amendment to the CARES Act provided for a five-year existing two-year loans to have terms of five to ten years . The loans are 100% guaranteed by the SBA. The SBA pays the originating bank a processing fee ranging from 1.0% to 5.0% , based on the size of the loan. At June 30, 2020, Trustmark had outstanding 9,693 PPP loans totaling $939.8 million (net of $29.9 million of deferred fees and costs). Due to amount and nature of the PPP loans, these loans were not included in the LHFI portfolio and are presented separately in the accompanying consolidated balance sheet. The PPP loans are fully guaranteed by the SBA; therefore, no ACL was estimated for these loans. Goodwill Impairment Evaluation Trustmark tests goodwill for impairment at least annually and, more frequently, if events or changes in circumstances indicate that it is more likely than not that there is possible impairment. Considering the significant negative impact that the ongoing COVID-19 pandemic is having on the United States economy, Trustmark has determined that the COVID-19 pandemic represented a triggering event prompting an evaluation of goodwill impairment. Based on the qualitative evaluation performed, Trustmark concluded that goodwill was not more than likely impaired at June 30, 2020. However, in light of the on-going impact of the COVID-19 pandemic, Trustmark will continue to monitor its goodwill for possible impairment.

Securities Available for Sale a

Securities Available for Sale and Held to Maturity	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
Securities Available for Sale and Held to Maturity	Note 2 – Securities Available for Sale and Held to Maturity Financial Accounting Standards Board (FASB) Accounting Standard Update (ASU) 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” was adopted by Trustmark on January 1, 2020. ASU 2016-13 introduces the current expected credit losses methodology for estimating allowances for credit losses. ASU 2016-13 applies to all financial instruments carried at amortized cost, including securities held to maturity, and makes targeted improvements to the accounting for credit losses on securities available for sale. Under ASU 2016-13, the allowance for credit losses is an estimate measured using relevant information about past events, including historical credit loss experience on financial assets with similar risk characteristics, current conditions, and reasonable and supportable forecasts that affect the collectability of the remaining cash flows over the contractual term of the financial assets. In order to comply with ASU 2016-13, Trustmark conducted a review of its investment portfolio and determined that for certain classes of securities it would be appropriate to assume the expected credit loss to be zero. This zero-credit loss assumption applies to debt issuances of the U.S. Treasury and agencies and instrumentalities of the United States government. The reasons behind the adoption of the zero-credit loss assumption were as follows: • High credit rating • Long history with no credit losses • Guaranteed by a sovereign entity • Widely recognized as “risk-free rate” • Can print its own currency • Currency is routinely held by central banks, used in international commerce, and commonly viewed as reserve currency • Currently under the U.S. Government conservatorship or receivership Trustmark will continuously monitor any changes in economic conditions, credit downgrades, changes to explicit or implicit guarantees granted to certain debt issuers, and any other relevant information that would indicate potential credit deterioration and prompt Trustmark to reconsider its zero-credit loss assumption. At the date of adoption, Trustmark’s estimated allowance for credit losses on securities available for sale and held to maturity under ASU 2016-13 was deemed immaterial due to the composition of these portfolios. Both portfolios consist primarily of U.S. government agency guaranteed mortgage-backed securities for which the risk of loss is minimal. Therefore, Trustmark did not recognize a cumulative effect adjustment through retained earnings related to the available for sale or held to maturity securities. Securities Available for Sale ASU 2016-13 makes targeted improvements to the accounting for credit losses on securities available for sale. The concept of other-than-temporarily impaired has been replaced with the allowance for credit losses. Unlike securities held to maturity, securities available for sale are evaluated on an individual level and pooling of securities is not allowed. Quarterly, Trustmark evaluates if any securit y ha s a fair value less than its amortized cost. Once these securities are identified, in order to determine whether a d ecline in fair value result ed from a credit loss or other factors , Trustmark perform s further analysis as outlined below: • Review the extent to which the fair value is less than the amortized cost and observe the security’s lowest credit rating as reported by third-party credit ratings companies. • The securities that violate the credit loss triggers above would be subjected to additional analysis that may include, but is not limited to: changes in market interest rates, changes in securities credit ratings, security type, service area economic factors, financial performance of the issuer/or obligor of the underlying issue and third-party guarantee. • If Trustmark determines that a credit loss exists, the credit portion of the allowance will be measured using a discounted cash flow (DCF) analysis using the effective interest rate as of the security’s purchase date. The amount of credit loss Trustmark records will be limited to the amount by which the amortized cost exceeds the fair value. The DCF analysis utilizes contractual maturities, as well as third-party credit ratings and cumulative default rates published annually by Moody’s Investor Service (Moody’s). At June 30, 2020, the results of the analysis did not identify any securities that violate the credit loss triggers; therefore, no DCF analysis was performed and no credit loss was recognized on any of the securities available for sale. Accrued interest receivable is excluded from the estimate of credit losses for securities available for sale. At June 30, 2020, accrued interest receivable totaled $4.2 million for securities available for sale and was reported in other assets on the accompanying consolidated balance sheet. Securities Held to Maturity ASU 2016-13 requires institutions to measure expected credit losses on financial assets carried at amortized cost on a collective or pool basis when similar risks exist. Trustmark uses several levels of segmentation in order to measure expected credit losses: • The portfolio is segmented into agency and non-agency securities. • The non-agency securities are separated into municipal, mortgage, and corporate securities. Each individual segment is categorized by third-party credit ratings. As discussed above, Trustmark has determined that for certain classes of securities it would be appropriate to assume the expected credit loss to be zero, which include debt issuances of the U.S. Treasury and agencies and instrumentalities of the United States government. This assumption will be reviewed and attested to quarterly. Trustmark is using an internally built model to verify the accuracy of third-party provided calculations. At June 30, 2020, Trustmark’s securities held to maturity totaled $660.0 million. The potential credit loss exposure was $31.5 million and consisted of municipal securities. After applying appropriate probability of default and loss given default assumptions, the total amount of current expected credit losses was deemed immaterial. Therefore, no reserve was recorded at June 30, 2020. Accrued interest receivable is excluded from the estimate of credit losses for securities held to maturity. At June 30, 2020, accrued interest receivable totaled $1.4 million for securities held to maturity and was reported in other assets on the accompanying consolidated balance sheet. At June 30, 2020, Trustmark had no securities held to maturity that were past due 30 days or more as to principal or interest payments. Trustmark had no securities held to maturity classified as nonaccrual at June 30, 2020. Trustmark monitors the credit quality of securities held to maturity on a monthly basis through credit ratings. The following table presents the amortized cost of Trustmark’s securities held to maturity by credit rating, as determined by Moody’s, at June 30, 2020 ($ in thousands): Securities Held to Maturity June 30, 2020 Amortized Cost Aaa $ 628,419 Aa1 to Aa3 26,179 Not Rated (1) 5,450 Total $ 660,048 (1) Not rated securities primarily consist of Mississippi municipal general obligations. The following tables are a summary of the amortized cost and estimated fair value of securities available for sale and held to maturity at June 30, 2020 and December 31, 2019 ($ in thousands): Securities Available for Sale Securities Held to Maturity June 30, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. Government agency obligations $ 20,254 $ 160 $ (516 ) $ 19,898 $ — $ — $ — $ — Obligations of states and political subdivisions 10,565 611 — 11,176 31,629 461 (25 ) 32,065 Mortgage-backed securities Residential mortgage pass-through securities Guaranteed by GNMA 67,439 2,199 (1 ) 69,637 10,306 548 — 10,854 Issued by FNMA and FHLMC 1,096,861 24,762 (19 ) 1,121,604 86,346 3,204 — 89,550 Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 560,109 14,846 (15 ) 574,940 435,333 23,148 — 458,481 Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 84,350 2,558 (10 ) 86,898 96,434 3,177 — 99,611 Total $ 1,839,578 $ 45,136 $ (561 ) $ 1,884,153 $ 660,048 $ 30,538 $ (25 ) $ 690,561 December 31, 2019 U.S. Government agency obligations $ 22,965 $ 69 $ (707 ) $ 22,327 $ 3,781 $ 220 $ — $ 4,001 Obligations of states and political subdivisions 24,952 513 — 25,465 31,781 434 (53 ) 32,162 Mortgage-backed securities Residential mortgage pass-through securities Guaranteed by GNMA 69,196 425 (369 ) 69,252 10,820 266 (10 ) 11,076 Issued by FNMA and FHLMC 714,350 2,171 (3,165 ) 713,356 96,631 286 (370 ) 96,547 Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 656,162 3,777 (1,713 ) 658,226 485,324 7,026 (656 ) 491,694 Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 113,359 625 (206 ) 113,778 109,762 1,042 (82 ) 110,722 Total $ 1,600,984 $ 7,580 $ (6,160 ) $ 1,602,404 $ 738,099 $ 9,274 $ (1,171 ) $ 746,202 During 2013, Trustmark reclassified approximately $1.099 billion of securities available for sale to securities held to maturity. The securities were transferred at fair value, which became the cost basis for the securities held to maturity. At the date of transfer, the net unrealized holding loss on the available for sale securities totaled approximately $46.6 million ($28.8 million, net of tax). The net unrealized holding loss is amortized over the remaining life of the securities as a yield adjustment in a manner consistent with the amortization or accretion of the original purchase premium or discount on the associated security. There were no gains or losses recognized as a result of the transfer. At June 30, 2020, the net unamortized, unrealized loss on the transferred securities included in accumulated other comprehensive income (loss) in the accompanying balance sheet totaled approximately $10.5 million ($7.9 million, net of tax) compared to approximately $12.1 million ($9.1 million, net of tax) at December 31, 2019. The tables below include securities with gross unrealized losses for which an allowance for credit losses has not been recorded and segregated by length of impairment at June 30, 2020 and December 31, 2019 ($ in thousands): Less than 12 Months 12 Months or More Total June 30, 2020 Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses U.S. Government agency obligations $ — $ — $ 11,624 $ (516 ) $ 11,624 $ (516 ) Obligations of states and political subdivisions — — 6,221 (25 ) 6,221 (25 ) Mortgage-backed securities Residential mortgage pass-through securities Guaranteed by GNMA 325 (1 ) — — 325 (1 ) Issued by FNMA and FHLMC 20,644 (7 ) 8,954 (12 ) 29,598 (19 ) Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 2,436 (15 ) — — 2,436 (15 ) Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA — — 668 (10 ) 668 (10 ) Total $ 23,405 $ (23 ) $ 27,467 $ (563 ) $ 50,872 $ (586 ) December 31, 2019 U.S. Government agency obligations $ 6,585 $ (105 ) $ 12,886 $ (602 ) $ 19,471 $ (707 ) Obligations of states and political subdivisions — — 6,216 (53 ) 6,216 (53 ) Mortgage-backed securities Residential mortgage pass-through securities Guaranteed by GNMA 23,544 (107 ) 18,529 (272 ) 42,073 (379 ) Issued by FNMA and FHLMC 112,879 (230 ) 278,120 (3,305 ) 390,999 (3,535 ) Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 158,341 (738 ) 151,271 (1,631 ) 309,612 (2,369 ) Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 51,312 (167 ) 14,155 (121 ) 65,467 (288 ) Total $ 352,661 $ (1,347 ) $ 481,177 $ (5,984 ) $ 833,838 $ (7,331 ) The unrealized losses shown above are due to increases in market rates over the yields available at the time of purchase of the underlying securities and not credit quality. Trustmark does not intend to sell these securities and it is more likely than not that Trustmark will not be required to sell the investments before recovery of their amortized cost bases, which may be maturity. Prior to the adoption of FASB ASU 2016-13, Trustmark did not consider these investments to be other-than-temporarily impaired at June 30, 2019. There were no other-than-temporary impairments for the six months ended June 30, 2019. Security Gains and Losses During the three and six months ended June 30, 2020 and 2019, there were no gross realized gains or losses as a result of calls and dispositions of securities. Realized gains and losses are determined using the specific identification method and are included in noninterest income as security gains (losses), net. Securities Pledged Securities with a carrying value of $1.974 billion and $1.770 billion at June 30, 2020 and December 31, 2019, respectively, were pledged to collateralize public deposits and securities sold under repurchase agreements and for other purposes as permitted by law. At both June 30, 2020 and December 31, 2019, none of these securities were pledged under the Federal Reserve Discount Window program to provide additional contingency funding capacity. Contractual Maturities The amortized cost and estimated fair value of securities available for sale and held to maturity at June 30, 2020, by contractual maturity, are shown below ($ in thousands). Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Securities Available for Sale Securities Held to Maturity Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Due in one year or less $ 7,867 $ 7,945 $ 18,599 $ 18,715 Due after one year through five years 1,559 1,601 13,030 13,350 Due after five years through ten years 2,161 2,112 — — Due after ten years 19,232 19,416 — — 30,819 31,074 31,629 32,065 Mortgage-backed securities 1,808,759 1,853,079 628,419 658,496 Total $ 1,839,578 $ 1,884,153 $ 660,048 $ 690,561

Loans Held for Investment (LHFI

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI	6 Months Ended
	Jun. 30, 2020
Accounts Notes Loans And Financing Receivable Gross Allowance And Net [Abstract]
Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI	Note 3 – LHFI and Allowance for Credit Losses, LHFI Trustmark adopted the amendments of FASB ASU 2016-13, on January 1, 2020. The amendments of ASU 2016-13 created FASB Accounting Standards Codification (ASC) Topic 326, “Financial Instruments – Credit Losses,” which, among other things, replace much of the guidance and disclosures previously provided in FASB ASC Topic 310, “Receivables.” The guidance in FASB ASC Topic 326 replaces the incurred loss methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit losses. In accordance with FASB ASC Subtopic 326-20, “Financial Instruments – Credit Losses – Measured at Amortized Cost,” Trustmark has developed an allowance for credit losses (ACL) methodology effective January 1, 2020, which replaces its previous allowance for loan losses methodology. See the section captioned “Allowance for Credit Losses (ACL)” within this note for additional information regarding Trustmark’s ACL. Trustmark adopted FASB ASC Topic 326 using the modified retrospective approach prescribed by the amendments of ASU 2016-13; therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation. At June 30, 2020 and December 31, 2019, LHFI consisted of the following ($ in thousands): June 30, 2020 December 31, 2019 Loans secured by real estate: Construction, land development and other land $ 482,309 $ 1,162,791 Other secured by 1-4 family residential properties 562,828 1,855,913 Secured by nonfarm, nonresidential properties 2,610,392 2,475,245 Other real estate secured 884,815 724,480 Other loans secured by real estate: (1) Other construction 794,968 — Secured by 1-4 family residential properties 1,250,697 — Commercial and industrial loans 1,413,255 1,477,896 Consumer loans 164,560 175,738 State and other political subdivision loans 931,536 967,944 Other commercial loans (1) 564,446 495,621 LHFI 9,659,806 9,335,628 Less ACL 119,188 84,277 Net LHFI $ 9,540,618 $ 9,251,351 (1) In accordance with the guidance in FASB ASC Topic 326, Trustmark redefined its LHFI portfolio segments and related loan classes based on the level at which risk is monitored within the ACL methodology. The other loans secured by real estate portfolio segment and related loan classes were separated from the loans secured by real estate portfolio segment. The other construction loans were segregated from the construction, land development and other land loans. The other loans secured by 1-4 family residential properties were segregated from the loans secured by 1-4 family residential properties and the loans secured by 1-4 family residential properties were redefined in the other loans secured by real estate portfolio segment. Other loans were redefined as other commercial loans. Accrued interest receivable is not included in the amortized cost basis of Trustmark’s LHFI. At June 30, 2020, accrued interest receivable for LHFI totaled $35.6 million with no related ACL and was reported in other assets on the accompanying consolidated balance sheet. Loan Concentrations Trustmark does not have any loan concentrations other than those reflected in the preceding table, which exceed 10% of total LHFI. At June 30, 2020, Trustmark’s geographic loan distribution was concentrated primarily in its five key market regions: Alabama, Florida, Mississippi, Tennessee and Texas. Accordingly, the ultimate collectability of a substantial portion of these loans is susceptible to changes in market conditions in these areas. Nonaccrual and Past Due LHFI Past due LHFI are loans contractually past due 30 days or more as to principal or interest payments. A LHFI is classified as nonaccrual, and the accrual of interest on such loan is discontinued, when the contractual payment of principal or interest becomes 90 days past due on commercial credits and 120 days past due on non-business purpose credits. In addition, a credit may be placed on nonaccrual at any other time Management has serious doubts about further collectibility of principal or interest according to the contractual terms, even though the loan is currently performing. A LHFI may remain in accrual status if it is in the process of collection and well secured. When a LHFI is placed in nonaccrual status, interest accrued but not received is reversed against interest income. Interest payments received on nonaccrual LHFI are applied against principal under the cost-recovery method, until qualifying for return to accrual status. Under the cost-recovery method, interest income is not recognized until the principal balance is reduced to zero. LHFI are restored to accrual status when the obligation is brought current or has performed in accordance with the contractual terms for a reasonable period of time and the ultimate collectibility of the total contractual principal and interest is no longer in doubt. No material interest income was recognized in the income statement on nonaccrual LHFI for each of the periods ended June 30, 2020 and 2019. The following table provides the amortized cost basis of loans on nonaccrual status and loans past due 90 days or more still accruing interest as of June 30, 2020 ($ in thousands): June 30, 2020 Nonaccrual With No ACL Total Nonaccrual Loans Past Due 90 Days or More Still Accruing Loans secured by real estate: Construction, land development and other land $ 575 $ 932 $ — Other secured by 1-4 family residential properties 496 4,441 51 Secured by nonfarm, nonresidential properties 5,389 7,883 — Other real estate secured 63 881 — Other loans secured by real estate: Other construction — — — Secured by 1-4 family residential properties 1,480 12,523 528 Commercial and industrial loans 16,436 18,181 — Consumer loans — 120 217 State and other political subdivision loans — 4,049 — Other commercial loans 12 984 11 Total $ 24,451 $ 49,994 $ 807 The following table provides an aging analysis of the amortized cost basis of past due LHFI at June 30, 2020 ($ in thousands): June 30, 2020 Past Due 30-59 Days 60-89 Days 90 Days or Total Past Due Current Loans Total LHFI Loans secured by real estate: Construction, land development and other land $ 699 $ 323 $ 191 $ 1,213 $ 481,096 $ 482,309 Other secured by 1-4 family residential properties 1,481 1,017 632 3,130 559,698 562,828 Secured by nonfarm, nonresidential properties 187 391 682 1,260 2,609,132 2,610,392 Other real estate secured 165 — 288 453 884,362 884,815 Other loans secured by real estate: Other construction — — — — 794,968 794,968 Secured by 1-4 family residential properties 1,880 1,500 5,501 8,881 1,241,816 1,250,697 Commercial and industrial loans 594 99 2,001 2,694 1,410,561 1,413,255 Consumer loans 879 152 217 1,248 163,312 164,560 State and other political subdivision loans — — 177 177 931,359 931,536 Other commercial loans 351 16 446 813 563,633 564,446 Total $ 6,236 $ 3,498 $ 10,135 $ 19,869 $ 9,639,937 $ 9,659,806 The following table provides an aging analysis of past due and nonaccrual LHFI by loan class at December 31, 2019 ($ in thousands): December 31, 2019 Past Due 30-59 Days 60-89 Days 90 Days or (1) Total Nonaccrual Current Loans Total LHFI Loans secured by real estate: Construction, land development and other land $ 380 $ 256 $ — $ 636 $ 897 $ 1,161,258 $ 1,162,791 Secured by 1-4 family residential properties 5,254 940 211 6,405 16,810 1,832,698 1,855,913 Secured by nonfarm, nonresidential properties 1,698 — — 1,698 7,700 2,465,847 2,475,245 Other real estate secured 8 — — 8 1,032 723,440 724,480 Commercial and industrial loans 617 12 39 668 21,775 1,455,453 1,477,896 Consumer loans 2,208 380 392 2,980 108 172,650 175,738 State and other political subdivision loans 76 — — 76 4,079 963,789 967,944 Other loans 152 4 — 156 825 494,640 495,621 Total $ 10,393 $ 1,592 $ 642 $ 12,627 $ 53,226 $ 9,269,775 $ 9,335,628 (1) Past due 90 days or more but still accruing interest. Impaired LHFI Prior to the adoption of FASB ASC Topic 326, Trustmark’s individually evaluated impaired LHFI included all commercial nonaccrual relationships of $500 thousand or more, which were specifically reviewed for impairment and deemed impaired, and all LHFI classified as TDRs in accordance with FASB ASC Subtopic 310-10-50-20 “Impaired Loans.” Once a LHFI was deemed to be impaired, the full difference between book value and the most likely estimate of the collateral’s net realizable value was charged off or a specific reserve was established. No material interest income was recognized in the income statement on impaired LHFI for the periods ended June 30, 2019. At December 31, 2019, individually evaluated impaired LHFI consisted of the following ($ in thousands): December 31, 2019 LHFI Unpaid Principal Balance With No Related Allowance Recorded With an Allowance Recorded Total Recorded Investment Related Allowance Average Recorded Investment Loans secured by real estate: Construction, land development and other land $ 926 $ 610 $ 16 $ 626 $ — $ 1,089 Secured by 1-4 family residential properties 6,513 2,104 3,360 5,464 35 4,713 Secured by nonfarm, nonresidential properties 7,295 1,462 5,255 6,717 2,355 8,096 Other real estate secured 69 — 68 68 — 158 Commercial and industrial loans 27,178 19,374 4,084 23,458 707 27,088 Consumer loans 22 — 21 21 — 11 State and other political subdivision loans 4,079 — 4,079 4,079 1,809 6,337 Other loans 1,207 — 784 784 553 1,033 Total $ 47,289 $ 23,550 $ 17,667 $ 41,217 $ 5,459 $ 48,525 Troubled Debt Restructurings A TDR occurs when a borrower is experiencing financial difficulties, and for related economic or legal reasons, a concession is granted to the borrower that Trustmark would not otherwise consider. Whatever the form of concession that might be granted by Trustmark, Management’s objective is to enhance collectibility by obtaining more cash or other value from the borrower or by increasing the probability of receipt by granting the concession than by not granting it. Other concessions may arise from court proceedings or may be imposed by law. In addition, TDRs also include those credits that are extended or renewed to a borrower who is not able to obtain funds from sources other than Trustmark at a market interest rate for new debt with similar risk. At June 30, 2020 and 2019 , LHFI classified as TDRs totaled $ 26.9 million and $ million, respectively, and were primarily comprised of credits with interest-only payments for an extended period of time and credits renewed at a rate that was not commensurate with that of new debt with similar risk which totaled $ 14.6 million and $ million at June 30, 2020 and 2019 , respectively. The remaining TDRs at June 30, 2020 and 2019 resulted from bankruptcies or from payment or maturity extensions. Trustmark had $ 5.6 million of unused commitments on TDRs at June 30, 2020 compared to $ million of unused commitments on TDRs at June 30, 2019 . At June 30, 2020, TDRs had a related ACL of $2.0 million, compared to a related allowance for loan loss of $2.9 million at June 30, 2019, and resulted in charge-offs of $2.2 million and $117 thousand for the six months ended June 30, 2020 and 2019, respectively. The following table illustrates the impact of modifications classified as TDRs for the periods presented ($ in thousands): Three Months Ended June 30, 2020 2019 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Loans secured by real estate: Other secured by 1-4 family residential properties 3 $ 206 $ 210 5 $ 793 $ 792 Secured by nonfarm, nonresidential properties 1 139 139 1 5,055 5,055 Commercial and industrial loans — — — 2 113 — Consumer loans 2 6 6 — — — State and other political subdivision loans 2 3,902 3,872 — — — Total 8 $ 4,253 $ 4,227 8 $ 5,961 $ 5,847 Six Months Ended June 30, 2020 2019 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Loans secured by real estate: Other secured by 1-4 family residential properties 8 $ 707 $ 711 7 $ 879 $ 878 Secured by nonfarm, nonresidential properties 1 139 139 1 5,055 5,055 Commercial and industrial loans 2 1,582 1,582 8 9,167 9,054 Consumer loans 6 26 26 2 30 30 State and other political subdivision loans 2 3,902 3,872 — — — Total 19 $ 6,356 $ 6,330 18 $ 15,131 $ 15,017 The table below includes the balances at default for TDRs modified within the last 12 months for which there was a payment default during the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Number of Contracts Recorded Investment Number of Contracts Recorded Investment Loans secured by real estate: Other secured by 1-4 family residential properties 3 $ 420 1 $ 46 Secured by nonfarm, nonresidential properties 1 139 — — Commercial and industrial loans 1 82 10 7,957 Consumer loans — — 1 27 Total 5 $ 641 12 $ 8,030 Trustmark’s TDRs have resulted primarily from allowing the borrower to pay interest-only for an extended period of time and credits renewed at a rate that was not commensurate with that of new debt with similar risk rather than from forgiveness. Accordingly, as shown above, these TDRs have a similar recorded investment for both the pre-modification and post-modification disclosure. Trustmark has utilized loans 90 days or more past due to define payment default in determining TDRs that have subsequently defaulted. The following tables detail LHFI classified as TDRs by loan class at June 30, 2020 and 2019 ($ in thousands): June 30, 2020 Accruing Nonaccrual Total Loans secured by real estate: Construction, land development and other land $ — $ 14 $ 14 Other secured by 1-4 family residential properties 71 3,761 3,832 Secured by nonfarm, nonresidential properties — 3,010 3,010 Commercial and industrial loans 1,500 14,487 15,987 Consumer loans 18 21 39 State and other political subdivision loans — 3,872 3,872 Other commercial loans — 125 125 Total TDRs $ 1,589 $ 25,290 $ 26,879 June 30, 2019 Accruing Nonaccrual Total Loans secured by real estate: Construction, land development and other land $ — $ 20 $ 20 Secured by 1-4 family residential properties 50 3,563 3,613 Secured by nonfarm, nonresidential properties — 5,311 5,311 Commercial and industrial loans 14,897 11,965 26,862 Consumer loans — 30 30 Other loans — 510 510 Total TDRs $ 14,947 $ 21,399 $ 36,346 On March 27, 2020, the CARES Act, a stimulus package intended to provide relief to businesses and consumers in the United States struggling as a result of the pandemic, was signed into law. Section 4013 of the CARES Act also addressed COVID-19- related modifications and specified that COVID-19 related modifications executed between March 1, 2020 and the earlier of (i) 60 days after the date of termination of the national emergency declared by the President and (ii) December 31, 2020, on loans that were current as of December 31, 2019 are not TDRs. Additionally, under guidance from the federal banking agencies, other short-term modifications made on a good faith basis in response to COVID-19 to borrowers who were current prior to any relief are not TDRs under ASC Subtopic 310-40, “Troubled Debt Restructuring by Creditors.” These modifications include short-term (e.g., up to six months) modifications such as payment deferrals, fee waivers, extensions of repayment terms, or delays in payment that are insignificant. Borrowers considered current are those that are less than 30 days past due on their contractual payments at the time a modification program is implemented. Trustmark modified 2,692 individual loans with aggregate principal balances totaling $1.422 billion through June 30, 2020 without treating such modifications as TDRs. Commercial concessions were primarily either interest only for 90 days or full payment deferrals for 90 days. Consumer concessions were 90-day full payment deferrals. Collateral-Dependent Loans The following table presents the amortized cost basis of collateral-dependent loans by class of loans and collateral type as of June 30, 2020 ($ in thousands): June 30, 2020 Real Estate Equipment and Machinery Inventory and Receivables Vehicles Miscellaneous Total Loans secured by real estate: Construction, land development and other land $ 1,948 $ — $ — $ — $ — $ 1,948 Other secured by 1-4 family residential properties 496 — — — — 496 Secured by nonfarm, nonresidential properties 11,966 — — — — 11,966 Other real estate secured 63 — — — — 63 Other loans secured by real estate: Other construction — — — — — — Secured by 1-4 family residential properties 1,480 — — — — 1,480 Commercial and industrial loans 105 840 6,439 186 8,794 16,364 Consumer loans — — — — — — State and other political subdivision loans 4,049 — — — — 4,049 Other commercial loans 623 — 2,021 — 3,120 5,764 Total $ 20,730 $ 840 $ 8,460 $ 186 $ 11,914 $ 42,130 A loan is collateral dependent when the borrower is experiencing financial difficulty and repayment of the loan is expected to be provided substantially through the sale of the collateral. The following provides a qualitative description by class of loan of the collateral that secures Trustmark’s collateral-dependent LHFI: • Loans secured by real estate – Loans within these loan classes are secured by liens on real estate properties. There have been no significant changes to the collateral that secures these financial assets during the period. • Other loans secured by real estate – Loans within these loan classes are secured by liens on real estate properties. There have been no significant changes to the collateral that secures these financial assets during the period. • Commercial and industrial loans – Loans within this loan class are primarily secured by inventory, accounts, equipment and other non-real estate collateral. There have been no significant changes to the collateral that secures these financial assets during the period. • State and other political subdivision loans – Loans within this loan class are secured by liens on real estate properties. There have been no significant changes to the collateral that secures these financial assets during the period. • Other loans - Loans within this loan class are secured by liens on real estate properties or priority status of a UCC agreement for non-real estate collateral. There have been no significant changes to the collateral that secures these financial assets during the period. Credit Quality Indicators Trustmark’s LHFI portfolio credit quality indicators focus on six key quality ratios that are compared against bank tolerances. The loan indicators are total classified outstanding, total criticized outstanding, nonperforming loans, nonperforming assets, delinquencies and net loan losses. Due to the homogenous nature of consumer loans, Trustmark does not assign a formal internal risk rating to each credit and therefore the criticized and classified measures are primarily composed of commercial loans. In addition to monitoring portfolio credit quality indicators, Trustmark also measures how effectively the lending process is being managed and risks are being identified. As part of an ongoing monitoring process, Trustmark grades the commercial portfolio segment as it relates to credit file completion and financial statement exceptions, underwriting, collateral documentation and compliance with law as shown below: • Credit File Completeness and Financial Statement Exceptions – evaluates the quality and condition of credit files in terms of content and completeness and focuses on efforts to obtain and document sufficient information to determine the quality and status of credits. Also included is an evaluation of the systems/procedures used to insure compliance with policy. • Underwriting – evaluates whether credits are adequately analyzed, appropriately structured and properly approved within loan policy requirements. A properly approved credit is approved by adequate authority in a timely manner with all conditions of approval fulfilled. Total policy exceptions measure the level of underwriting and other policy exceptions within a portfolio segment. • Collateral Documentation – focuses on the adequacy of documentation to perfect Trustmark’s collateral position and substantiate collateral value. Collateral exceptions measure the level of documentation exceptions within a portfolio segment. Collateral exceptions occur when certain collateral documentation is either not present or not current. • Compliance with Law – focuses on underwriting, documentation, approval and reporting in compliance with banking laws and regulations. Primary emphasis is directed to the Financial Institutions Reform, Recovery and Enforcement Act of 1989 (FIRREA), Regulation O requirements and regulations governing appraisals. Commercial Credits Trustmark has established a loan grading system that consists of ten individual credit risk grades (risk ratings) that encompass a range from loans where the expectation of loss is negligible to loans where loss has been established. The model is based on the risk of default for an individual credit and establishes certain criteria to delineate the level of risk across the ten unique credit risk grades. Credit risk grade definitions are as follows: • Risk Rate (RR) 1 through RR 6 – Grades one through six represent groups of loans that are not subject to criticism as defined in regulatory guidance. Loans in these groups exhibit characteristics that represent low to moderate risk measured by using a variety of credit risk criteria such as cash flow coverage, debt service coverage, balance sheet leverage, liquidity, management experience, industry position, prevailing economic conditions, support from secondary sources of repayment and other credit factors that may be relevant to a specific loan. In general, these loans are supported by properly margined collateral and guarantees of principal parties. • Other Assets Especially Mentioned (Special Mention) (RR 7) – a loan that has a potential weakness that if not corrected will lead to a more severe rating. This rating is for credits that are currently protected but potentially weak because of an adverse feature or condition that if not corrected will lead to a further downgrade. • Substandard (RR 8) – a loan that has at least one identified weakness that is well defined. This rating is for credits where the primary sources of repayment are not viable at the time of evaluation or where either the capital or collateral is not adequate to support the loan and the secondary means of repayment do not provide a sufficient level of support to offset the identified weakness. Loss potential exists in the aggregate amount of substandard loans but does not necessarily exist in individual loans. • Doubtful (RR 9) – a loan with an identified weakness that does not have a valid secondary source of repayment. Generally, these credits have an impaired primary source of repayment and secondary sources are not sufficient to prevent a loss in the credit. The exact amount of the loss has not been determined at this time. • Loss (RR 10) – a loan or a portion of a loan that is deemed to be uncollectible. By definition, credit risk grades special mention (RR 7), substandard (RR 8), doubtful (RR 9) and loss (RR 10) are criticized loans while substandard (RR 8), doubtful (RR 9) and loss (RR 10) are classified loans. These definitions are standardized by all bank regulatory agencies and are generally equally applied to each individual lending institution. The remaining credit risk grades are considered pass credits and are solely defined by Trustmark. To enhance this process, Trustmark has determined that loans will be individually assessed, and a formal analysis will be performed and based upon the analysis the loan will be written down to net realizable value. Trustmark will individually assess and remove loans from the pool in the following circumstances: • Commercial nonaccrual loans with total exposure of $500 thousand (excluding those portions of the debt that are government guaranteed or are secured by Trustmark deposits or marketable securities) or more. • Commercial accruing substandard loans with total exposure of $1.0 million (excluding those portions of the debt that are government guaranteed or are secured by Trustmark deposits or marketable securities) or more will be reviewed on an individual basis to determine if the risk characteristics of the loan are indictive of the rest of the loan pool. Any loan that is believed to not share similar risk characteristics with the rest of the pool will be individually assessed. Otherwise, the loan will be left within the pool based on the results of the assessment. • Commercial accruing loans deemed to be a TDR with total exposure of $500 thousand (excluding those portions of the debt that are government guaranteed or are secured by Trustmark deposits or marketable securities) or more. If the loan is believed to not share similar risk characteristics with the rest of the loan pool, the loan will be individually assessed. Otherwise, the loan will be left within the pool and monitored on an ongoing basis. Each loan officer assesses the appropriateness of the internal risk rating assigned to their credits on an ongoing basis. Trustmark’s Asset Review area conducts independent credit quality reviews of the majority of Trustmark’s commercial loan portfolio both on the underlying credit quality of each individual loan class as well as the adherence to Trustmark’s loan policy and the loan administration process. In addition to the ongoing internal risk rate monitoring described above, Trustmark’s Credit Quality Review Committee meets monthly and performs a review of all loans of $100 thousand or more that are either delinquent thirty days or more or on nonaccrual. This review includes recommendations regarding risk ratings, accrual status, charge-offs and appropriate servicing officer as well as evaluation of problem credits for determination of TDRs. Quarterly, the Credit Quality Review Committee reviews and modifies continuous action plans for all credits risk rated seven or worse for relationships of $100 thousand or more. In addition, periodic reviews of significant development, commercial construction, multi-family and nonowner-occupied projects are performed. These reviews assess each particular project with respect to location, project valuations, progress of completion, leasing status, current financial information, rents, operating expenses, cash flow, adherence to budget and projections and other information as applicable. Summary results are reviewed by Senior and Regional Credit Officers in addition to the Chief Credit Officer with a determination made as to the appropriateness of existing risk ratings and accrual status. Consumer Credits Consumer LHFI that do not meet a minimum custom credit score are reviewed quarterly by Management. The Retail Credit Review Committee reviews the volume and percentage of approvals that did not meet the minimum passing custom score by region, individual location, and officer to ensure that Trustmark continues to originate quality loans. Trustmark monitors the levels and severity of past due consumer LHFI on a daily basis through its collection activities. A detailed assessment of consumer LHFI delinquencies is performed monthly at both a product and market level by delivery channel, which incorporates the perceived level of risk at time of underwriting. The tables below present the amortized cost basis of loans by credit quality indicator and class of loans based on the most recent analysis performed ($ in thousands): Term Loans by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Total As of June 30, 2020 Commercial LHFI Loans secured by real estate: Construction, land development and other land: Pass - RR 1 through RR 6 $ 170,118 $ 146,424 $ 36,674 $ 5,413 $ 3,571 $ 5,192 $ 37,106 $ 404,498 Special Mention - RR 7 — — — — — — — — Substandard - RR 8 2,417 74 495 47 680 26 — 3,739 Doubtful - RR 9 — — — — — 42 — 42 Total 172,535 146,498 37,169 5,460 4,251 5,260 37,106 408,279 Other secured by 1-4 family residential properties: Pass - RR 1 through RR 6 $ 21,491 $ 28,901 $ 22,057 $ 11,956 $ 14,141 $ 8,565 $ 7,010 $ 114,121 Special Mention - RR 7 — 90 — — — — — 90 Substandard - RR 8 4,694 299 1,032 240 71 790 — 7,126 Doubtful - RR 9 33 1 — — — — — 34 Total 26,218 29,291 23,089 12,196 14,212 9,355 7,010 121,371 Secured by nonfarm, nonresidential properties: Pass - RR 1 through RR 6 $ 315,293 $ 519,415 $ 466,036 $ 384,595 $ 332,457 $ 424,260 $ 108,032 $ 2,550,088 Special Mention - RR 7 — 5,655 1,083 — 350 4,894 — 11,982 Substandard - RR 8 8,866 10,821 1,827 3,586 9,131 12,583 921 47,735 Doubtful - RR 9 57 180 — — — 331 — 568 Total 324,216 536,071 468,946 388,181 341,938 442,068 108,953 2,610,373 Other real estate secured: Pass - RR 1 through RR 6 $ 67,416 $ 181,243 $ 295,676 $ 160,526 $ 130,810 $ 35,183 $ 10,314 $ 881,168 Special Mention - RR 7 — — — — — 874 — 874 Substandard - RR 8 1,201 187 18 — 63 715 — 2,184 Doubtful - RR 9 — — — — — — — — Total 68,617 181,430 295,694 160,526 130,873 36,772 10,314 884,226 Term Loans by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Total As of June 30, 2020 Commercial LHFI Other loans secured by real estate: Other construction Pass - RR 1 through RR 6 $ 63,346 $ 448,004 $ 235,925 $ 25,957 $ 1,481 $ — $ 6,858 $ 781,571 Special Mention - RR 7 — — — — — — — — Substandard - RR 8 13,397 — — — — — — 13,397 Doubtful - RR 9 — — — — — — — — Total 76,743 448,004 235,925 25,957 1,481 — 6,858 794,968 Commercial and industrial loans: Pass - RR 1 through RR 6 $ 301,484 $ 281,419 $ 115,890 $ 95,696 $ 82,537 $ 56,802 $ 434,958 $ 1,368,786 Special Mention - RR 7 850 — — — — — 833 1,683 Substandard - RR 8 10,630 2,512 15,481 344 628 2,581 10,089 42,265 Doubtful - RR 9 48 402 — — 43 4 24 521 Total 313,012 284,333 131,371 96,040 83,208 59,387 445,904 1,413,255 State and other political subdivision loans: Pass - RR 1 through RR 6 $ 85,513 $ 109,844 $ 54,240 $ 119,532 $ 144,165 $ 408,276 $ 898 $ 922,468 Special Mention - RR 7 — — — — — 4,000 — 4,000 Substandard - RR 8 — — — 339 — 4,729 — 5,068 Doubtful - RR 9 — — — — — — — — Total 85,513 109,844 54,240 119,871 144,165 417,005 898 931,536 Other commercial loans: Pass - RR 1 through RR 6 $ 66,388 $ 83,965 $ 28,885 $ 14,821 $ 57,952 $ 54,114 $ 224,792 $ 530,917 Special Mention - RR 7 7,917 — — — — — 11,833 19,750 Substandard - RR 8 98 2,190 686 45 1,063 1 9,670 13,753 Doubtful - RR 9 — 3 — — — 23 — 26 Total 74,403 86,158 29,571 14,866 59,015 54,138 246,295 564,446 Total commercial LHFI $ 1,141,257 $ 1,821,629 $ 1,276,005 $ 823,097 $ 779,143 $ 1,023,985 $ 863,338 $ 7,728,454 Term Loans by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Total As of June 30, 2020 Consumer LHFI Loans secured by real estate: Construction, land development and other land: Current $ 15,175 $ 39,837 $ 10,387 $ 2,398 $ 1,784 $ 3,955 $ — $ 73,536 Past due 30-89 days — — 323 — — 45 — 368 Past due 90 days or more — — — — — — — — Nonaccrual — — — — 19 107 — 126 Total 15,175 39,837 10,710 2,398 1,803 4,107 — 74,030 Other secured by 1-4 family residential properties: Current $ 11,365 $ 19,349 $ 14,814 $ 4,464 $ 2,697 $ 16,646 $ 367,313 $ 436,648 Past due 30-89 days — 210 162 — 58 155 914 1,499 Past due 90 days or more — — — — — 13 38 51 Nonaccrual — 35 144 470 — 564 2,046 3,259 Total 11,365 19,594 15,120 4,934 2,755 17,378 370,311 441,457 Secured by nonfarm, nonresidential properties: Current $ — $ — $ — $ 5 $ — $ 14 $ — $ 19 Past due 30-89 days — — — — — — — — Past due 90 days or more — — — — — — — — Nonaccrual — — — — — — — — Total — — — 5 — 14 — 19 Other real estate secured: Current $ 91 $ — $ 44 $ 46 $ 106 $ 302 $ — $ 589 Past due 30-89 days — — — — — — — — Past due 90 days or more — — — — — — — — Nonaccrual — — — — — — — — Total 91 — 44 46 106 302 — 589 Term Loans by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Total As of June 30, 2020 Consumer LHFI Other loans secured by real estate: Secured by 1-4 family residential properties Current $ 137,146 $ 242,961 $ 218,993 $ 115,354 $ 130,831 $ 390,425 $ — $ 1,235,710 Past due 30-89 days 73 85 77 123 79 1,497 — 1,934 Past due 90 days or more — — — 139 — 390 — 529 Nonaccrual 44 713 2,507 467 558 8,235 — 12,524 Total 137,263 243,759 221,577 116,083 131,468 400,547 — 1,250,697 Consumer loans: Current $ 38,

Acquired Loans

Acquired Loans	6 Months Ended
	Jun. 30, 2020
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities [Abstract]
Acquired Loans	Note 4 – Acquired Loans Trustmark’s loss-share agreement with the Federal Deposit Insurance Corporation (FDIC) covering the acquired covered loans secured by 1-4 family residential properties will expire in 2021. Upon adoption of FASB ASC Topic 326, which was effective for Trustmark on January 1, 2020 in accordance with the amendments in FASB ASU 2016-13, Trustmark elected to account for its existing acquired loans as purchased credit deteriorated (PCD) loans included within the LHFI portfolio. Trustmark elected to maintain pools of loans that were previously accounted for under FASB ASC Subtopic 310-30, “Receivables – Loans and Debt Securities Acquired with Deteriorated Credit Quality,” and will continue to account for these pools as a unit of account. Loans are only removed from the existing loan pools if they are written off, paid off or sold. Upon adoption of FASB ASC Topic 326, the ACL was determined for each pool and added to the pool’s carrying value to establish a new amortized cost basis. The difference between the unpaid principal balance of the pool and the new amortized cost basis is the noncredit premium or discount which will be amortized into interest income over the remaining life of the pool. Changes to the allowance for credit losses after adoption of FASB ASC Topic 326 are recorded through the PCL. Consequently, acquired loans of $72.6 million, as well as the allowance for loan losses, acquired loans of $815 thousand, were transferred on January 1, 2020. At December 31, 2019, acquired loans consisted of the following ($ in thousands): December 31, 2019 Loans secured by real estate: Construction, land development and other land $ 4,771 Secured by 1-4 family residential properties 17,525 Secured by nonfarm, nonresidential properties 38,206 Other real estate secured 3,946 Commercial and industrial loans 5,035 Consumer loans 520 Other loans 2,598 Acquired loans 72,601 Less allowance for loan losses, acquired loans 815 Net acquired loans $ 71,786 The following table presents changes in the net carrying value of the acquired loans for the periods presented ($ in thousands): Acquired Impaired Acquired Not ASC 310-30 (1) Carrying value, net at January 1, 2019 $ 102,890 $ 2,811 Transfers (2) — (2,926 ) Accretion to interest income 5,532 115 Payments received, net (37,230 ) — Other (3) 178 — Change in allowance for loan losses, acquired loans 416 — Carrying value, net at December 31, 2019 71,786 — FASB ASU 2016-13 adoption adjustment (71,786 ) — Accretion to interest income — — Payments received, net — — Other (3) — — Change in allowance for loan losses, acquired loans — — Carrying value, net at June 30, 2020 $ — $ — (1) “Acquired Not ASC 310-30” loans consist of loans that are not in scope for FASB ASC Subtopic 310-30. (2) “Acquired Not ASC 310-30” ( 3 ) Includes miscellaneous timing adjustments as well as acquired loan terminations through foreclosure, charge-off and other terminations. Under FASB ASC Subt opic 310-30, the accretable yield is the excess of expected cash flows at acquisition over the initial fair value of acquired impaired loans and is recorded as interest income over the estimated life of the loans using the effective yield method if the timing and amount of the future cash flows is reasonably estimable. The following table presents changes in the accretable yield for the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Accretable yield at beginning of period $ (14,816 ) $ (17,722 ) FASB ASU 2016-13 adoption adjustment 14,816 — Accretion to interest income — 2,983 Disposals, net — 1,114 Reclassification from nonaccretable difference (1) — (2,280 ) Accretable yield at end of period $ — $ (15,905 ) (1) Reclassifications from nonaccretable difference are due to lower loss expectations and improvements in expected cash flows. The following table presents the components of the allowance for loan losses on acquired loans for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Balance at beginning of period $ — $ 1,297 $ 815 $ 1,231 FASB ASU 2016-13 adoption adjustment — — (815 ) — Net (charge-offs) recoveries — (5 ) — (17 ) Provision for loan losses, acquired loans — 106 — 184 Balance at end of period $ — $ 1,398 $ — $ 1,398 The table below presents the acquired loans by loan class and credit quality indicator at December 31, 2019 ($ in thousands): December 31, 2019 Commercial Loans Pass - Categories 1-6 Special Mention - Category 7 Substandard - Category 8 Doubtful - Category 9 Subtotal Loans secured by real estate: Construction, land development and other land $ 4,022 $ — $ 192 $ — $ 4,214 Secured by 1-4 family residential properties 3,164 42 580 — 3,786 Secured by nonfarm, nonresidential properties 27,848 — 9,972 386 38,206 Other real estate secured 3,878 — 68 0 3,946 Commercial and industrial loans 3,419 — — 1,616 5,035 Consumer loans — — — — — Other loans 2,591 — 7 — 2,598 Total acquired loans $ 44,922 $ 42 $ 10,819 $ 2,002 $ 57,785 Consumer Loans Current Past Due 30-89 Days Past Due 90 Days or More Nonaccrual (1) Subtotal Total Acquired Loans Loans secured by real estate: Construction, land development and other land $ 463 $ 94 $ — $ — $ 557 $ 4,771 Secured by 1-4 family residential properties 12,843 615 281 — 13,739 17,525 Secured by nonfarm, nonresidential properties — — — — — 38,206 Other real estate secured — — — — — 3,946 Commercial and industrial loans — — — — — 5,035 Consumer loans 489 31 — — 520 520 Other loans — — — — — 2,598 Total acquired loans $ 13,795 $ 740 $ 281 $ — $ 14,816 $ 72,601 (1) Acquired loans not accounted for under FASB ASC Subtopic 310-30. The following table provides an aging analysis of contractually past due and nonaccrual acquired loans at December 31, 2019 ($ in thousands): December 31, 2019 Past Due 30-59 Days 60-89 Days 90 Days or More (1) Total Nonaccrual (2) Current Loans Total Acquired Loans Loans secured by real estate: Construction, land development and other land $ 94 $ — $ 38 $ 132 $ — $ 4,639 $ 4,771 Secured by 1-4 family residential properties 696 131 366 1,193 — 16,332 17,525 Secured by nonfarm, nonresidential properties 36 — 851 887 — 37,319 38,206 Other real estate secured 1 — 52 53 — 3,893 3,946 Commercial and industrial loans — — — — — 5,035 5,035 Consumer loans 16 15 — 31 — 489 520 Other loans — — — — — 2,598 2,598 Total acquired loans $ 843 $ 146 $ 1,307 $ 2,296 $ — $ 70,305 $ 72,601 (1) Past due 90 days or more but still accruing interest. (2) Acquired loans not accounted for under FASB ASC Subtopic 310-30.

Mortgage Banking

Mortgage Banking	6 Months Ended
	Jun. 30, 2020
Mortgage Banking [Abstract]
Mortgage Banking	Note 5 – Mortgage Banking Mortgage Servicing Rights The activity in the mortgage servicing rights (MSR) is detailed in the table below for the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Balance at beginning of period $ 79,394 $ 95,596 Origination of servicing assets 12,396 6,075 Change in fair value: Due to market changes (27,158 ) (17,072 ) Due to run-off (6,821 ) (5,316 ) Balance at end of period $ 57,811 $ 79,283 Trustmark determines the fair value of the MSR using a valuation model administered by a third party that calculates the present value of estimated future net servicing income. Trustmark considers the conditional prepayment rate (CPR), which is an estimated loan prepayment rate that uses historical prepayment rates for previous loans similar to the loans being evaluated, and the discount rate in determining the fair value of the MSR. An increase in either the CPR or discount rate assumption will result in a decrease in the fair value of the MSR, while a decrease in either assumption will result in an increase in the fair value of the MSR. At June 30, 2020, the fair value of the MSR included an assumed average prepayment speed of 17 CPR and an average discount rate of 9.58% compared to an assumed average prepayment speed of 12 CPR and an average discount rate of 10.04% at June 30, 2019. Mortgage Loans Serviced/Sold During the first six months of 2020 and 2019, Trustmark sold $1.103 billion and $488.1 million, respectively, of residential mortgage loans. Gains on these sales were recorded as noninterest income in mortgage banking, net and totaled $48.4 million for the first six months of 2020 compared to $12.5 million for the first six months of 2019. The table below details the mortgage loans sold and serviced for others at June 30, 2020 and December 31, 2019 ($ in thousands): June 30, 2020 December 31, 2019 Federal National Mortgage Association $ 4,535,557 $ 4,411,914 Government National Mortgage Association 2,774,839 2,652,782 Federal Home Loan Mortgage Corporation 64,232 73,134 Other 18,012 19,404 Total mortgage loans sold and serviced for others $ 7,392,640 $ 7,157,234 Trustmark is subject to losses in its loan servicing portfolio due to loan foreclosures. Trustmark has obligations to either repurchase the outstanding principal balance of a loan or make the purchaser whole for the economic benefits of a loan if it is determined that the loan sold was in violation of representations or warranties made by Trustmark at the time of the sale, herein referred to as mortgage loan servicing putback expenses. Such representations and warranties typically include those made regarding loans that had missing or insufficient file documentation, loans that do not meet investor guidelines, loans in which the appraisal does not support the value and/or loans obtained through fraud by the borrowers or other third parties. Generally, putback requests may be made until the loan is paid in full. However, mortgage loans delivered to Federal National Mortgage Association (FNMA) and Federal Home Loan Mortgage Corporation (FHLMC) on or after January 1, 2013 are subject to the Lending and Selling Representations and Warranties Framework updated in May 2014, which provides certain instances in which FNMA and FHLMC will not exercise their remedies, including a putback request, for breaches of certain selling representations and warranties, such as payment history and quality control review. When a putback request is received, Trustmark evaluates the request and takes appropriate actions based on the nature of the request. Trustmark is required by FNMA and FHLMC to provide a response to putback requests within 60 days of the date of receipt. The total mortgage loan servicing putback expenses are included in other expense. At June 30, 2020 and 2019, Trustmark had a reserve for mortgage loan servicing putback expenses of $500 thousand and $702 thousand, respectively. There is inherent uncertainty in reasonably estimating the requirement for reserves against potential future mortgage loan servicing putback expenses. Future putback expenses are dependent on many subjective factors, including the review procedures of the purchasers and the potential refinance activity on loans sold with servicing released and the subsequent consequences under the representations and warranties. Trustmark believes that it has appropriately reserved for potential mortgage loan servicing putback requests.

Other Real Estate

Other Real Estate	6 Months Ended
	Jun. 30, 2020
Other Real Estate And Foreclosed Assets [Abstract]
Other Real Estate	Note 6 – Other Real Estate At June 30, 2020, Trustmark’s geographic other real estate distribution was concentrated primarily in its five key market regions: Alabama, Florida, Mississippi, Tennessee and Texas. The ultimate recovery of a substantial portion of the carrying amount of other real estate is susceptible to changes in market conditions in these areas. For the periods presented, changes and gains (losses), net on other real estate were as follows ($ in thousands): Six Months Ended June 30, 2020 2019 Balance at beginning of period $ 29,248 $ 34,668 Additions 406 2,101 Disposals (10,534 ) (3,859 ) Write-downs (844 ) (1,667 ) Balance at end of period $ 18,276 $ 31,243 Gains (losses), net on the sale of other real estate included in other real estate expense $ (255 ) $ 246 At June 30, 2020 and December 31, 2019, other real estate by type of property consisted of the following ($ in thousands): June 30, 2020 December 31, 2019 Construction, land development and other land properties $ 8,341 $ 11,482 1-4 family residential properties 1,992 3,453 Nonfarm, nonresidential properties 7,943 14,313 Total other real estate $ 18,276 $ 29,248 At June 30, 2020 and December 31, 2019, other real estate by geographic location consisted of the following ($ in thousands): June 30, 2020 December 31, 2019 Alabama $ 4,766 $ 8,133 Florida 3,665 5,877 Mississippi (1) 9,408 14,919 Tennessee (2) 437 319 Texas — — Total other real estate $ 18,276 $ 29,248 (1) Mississippi includes Central and Southern Mississippi Regions. (2) Tennessee includes Memphis, Tennessee and Northern Mississippi Regions. At June 30, 2020 and December 31, 2019, the balance of other real estate included $2.0 million and $3.5 million, respectively, of foreclosed residential real estate properties recorded as a result of obtaining physical possession of the property. At June 30, 2020 and December 31, 2019, the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process was $333 thousand and $953 thousand, respectively.

Leases

Leases	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Leases	Note 7 – Leases The following table details the components of net lease cost for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Finance leases Amortization of right-of-use assets $ 481 $ 642 $ 978 $ 1,145 Interest on lease liabilities 65 80 132 161 Operating lease cost 1,289 1,289 2,579 2,589 Short-term lease cost 111 123 220 203 Variable lease cost 332 346 679 690 Sublease income (63 ) (82 ) (162 ) (169 ) Net lease cost $ 2,215 $ 2,398 $ 4,426 $ 4,619 The following table details the cash payments included in the measurement of lease liabilities during the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Finance leases Operating cash flows included in operating activities $ 132 $ 526 Financing cash flows included in payments under finance lease obligations 905 1,035 Operating leases Operating cash flows (fixed payments) included in other operating activities, net 2,493 2,481 Operating cash flows (liability reduction) included in other operating activities, net 1,949 1,875 The following table details balance sheet information, as well as weighted-average lease terms and discount rates, related to leases at June 30, 2020 and December 31, 2019 ($ in thousands): June 30, 2020 December 31, 2019 Finance lease right-of-use assets, net of accumulated depreciation $ 8,348 $ 9,326 Finance lease liabilities 8,616 9,520 Operating lease right-of-use assets 29,819 31,182 Operating lease liabilities 31,076 32,354 Weighted-average lease term Finance leases 8.58 years 8.62 years Operating leases 8.72 years 9.05 years Weighted-average discount rate Finance leases 3.05 % 3.01 % Operating leases 3.49 % 3.51 % At June 30, 2020, future minimum rental commitments under finance and operating leases were as follows ($ in thousands): Finance Leases Operating Leases 2020 (excluding the six months ended June 30, 2020) $ 1,740 $ 4,890 2021 1,617 4,355 2022 1,350 4,139 2023 549 4,102 2024 582 3,994 Thereafter 4,161 14,738 Total minimum lease payments 9,999 36,218 Less imputed interest (1,383 ) (5,142 ) Lease liabilities $ 8,616 $ 31,076

Deposits

Deposits	6 Months Ended
	Jun. 30, 2020
Deposits [Abstract]
Deposits	Note 8 – Deposits At June 30, 2020 and December 31, 2019, deposits consisted of the following ($ in thousands): June 30, 2020 December 31, 2019 Noninterest-bearing demand $ 3,880,540 $ 2,891,215 Interest-bearing demand 4,037,460 3,125,914 Savings 4,075,127 3,590,509 Time 1,512,346 1,637,919 Total $ 13,505,473 $ 11,245,557

Securities Sold Under Repurchas

Securities Sold Under Repurchase Agreements	6 Months Ended
	Jun. 30, 2020
Securities Sold Under Agreements To Repurchase [Abstract]
Securities Sold Under Repurchase Agreements	Note 9 – Securities Sold Under Repurchase Agreements Trustmark utilizes securities sold under repurchase agreements as a source of borrowing in connection with overnight repurchase agreements offered to commercial deposit customers by using its unencumbered investment securities as collateral. Trustmark accounts for its securities sold under repurchase agreements as secured borrowings in accordance with FASB ASC Subtopic 860-30, “Transfers and Servicing – Secured Borrowing and Collateral.” Securities sold under repurchase agreements are stated at the amount of cash received in connection with the transaction. Trustmark monitors collateral levels on a continual basis and may be required to provide additional collateral based on the fair value of the underlying securities. Securities sold under repurchase agreements were secured by securities with a carrying amount of $93.7 million and $105.6 million at June 30, 2020 and December 31, 2019, respectively. Trustmark’s repurchase agreements are transacted under master repurchase agreements that give Trustmark, in the event of default by the counterparty, the right of offset with the same counterparty. As of June 30, 2020, all repurchase agreements were short-term and consisted primarily of sweep repurchase arrangements, under which excess deposits are “swept” into overnight repurchase agreements with Trustmark. The following table presents the securities sold under repurchase agreements by collateral pledged at June 30, 2020 and December 31, 2019 ($ in thousands): June 30, 2020 December 31, 2019 Mortgage-backed securities Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA $ 23,780 $ 24,282 Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 29,742 29,290 Total securities sold under repurchase agreements $ 53,522 $ 53,572

Revenue from Contracts with Cus

Revenue from Contracts with Customers	6 Months Ended
	Jun. 30, 2020
Revenue From Contract With Customer [Abstract]
Revenue from Contracts with Customers	Note 10 – Revenue from Contracts with Customers Trustmark accounts for revenue from contracts with customers in accordance with FASB ASC Topic 606, “Revenue from Contracts with Customers,” which provides that revenue be recognized in a manner that depicts the transfer of goods or services to a customer in an amount that reflects the consideration Trustmark expects to be entitled to in exchange for those goods or services. Revenue from contracts with customers is recognized either over time in a manner that depicts Trustmark’s performance, or at a point in time when control of the goods or services are transferred to the customer. Trustmark’s noninterest income, excluding all of mortgage banking, net and securities gains (losses), net and portions of bank card and other fees and other income, are considered within the scope of FASB ASC Topic 606. Gains or losses on the sale of other real estate, which are included in Trustmark’s noninterest expense as other real estate expense, are also within the scope of FASB ASC Topic 606. Trustmark records a gain or loss from the sale of other real estate when control of the property transfers to the buyer. Trustmark records the gain or loss from the sale of other real estate in noninterest expense as other real estate expense, net. Other real estate sales for the three and six months ended June 30, 2020 resulted in net losses of $185 thousand and $255 thousand, respectively, compared to net gains of $124 thousand and $246 thousand for the three and six months ended June 30, 2019, respectively. The following tables present noninterest income disaggregated by reportable operating segment and revenue stream for the periods presented ($ in thousands): Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Topic 606 Not Topic 606 (1) Total Topic 606 Not Topic 606 (1) Total General Banking Segment Service charges on deposit accounts $ 6,380 $ — $ 6,380 $ 10,357 $ — $ 10,357 Bank card and other fees 6,549 1,160 7,709 7,162 823 7,985 Mortgage banking, net — 33,745 33,745 — 10,295 10,295 Wealth management 79 — 79 97 — 97 Other, net 1,354 784 2,138 2,333 (259 ) 2,074 Total noninterest income $ 14,362 $ 35,689 $ 50,051 $ 19,949 $ 10,859 $ 30,808 Wealth Management Segment Service charges on deposit accounts $ 17 $ — $ 17 $ 22 $ — $ 22 Bank card and other fees 8 — 8 19 — 19 Wealth management 7,492 — 7,492 7,645 — 7,645 Other, net 24 9 33 25 29 54 Total noninterest income $ 7,541 $ 9 $ 7,550 $ 7,711 $ 29 $ 7,740 Insurance Segment Insurance commissions $ 11,868 $ — $ 11,868 $ 11,089 $ — $ 11,089 Other, net 42 — 42 2 — 2 Total noninterest income $ 11,910 $ — $ 11,910 $ 11,091 $ — $ 11,091 Consolidated Service charges on deposit accounts $ 6,397 $ — $ 6,397 $ 10,379 $ — $ 10,379 Bank card and other fees 6,557 1,160 7,717 7,181 823 8,004 Mortgage banking, net — 33,745 33,745 — 10,295 10,295 Insurance commissions 11,868 — 11,868 11,089 — 11,089 Wealth management 7,571 — 7,571 7,742 — 7,742 Other, net 1,420 793 2,213 2,360 (230 ) 2,130 Total noninterest income $ 33,813 $ 35,698 $ 69,511 $ 38,751 $ 10,888 $ 49,639 (1) Noninterest income not in scope for FASB ASC Topic 606 includes customer derivatives revenue and miscellaneous credit card fee income within bank card and other fees; mortgage banking, net; amortization of tax credits, accretion of the FDIC indemnification asset, cash surrender value on various life insurance policies, earnings on Trustmark’s non-qualified deferred compensation plans, other partnership investments and rental income within other, net; and security Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Topic 606 Not Topic 606 (1) Total Topic 606 Not Topic 606 (1) Total General Banking Segment Service charges on deposit accounts $ 16,392 $ — $ 16,392 $ 20,597 $ — $ 20,597 Bank card and other fees 13,275 (217 ) 13,058 14,027 1,125 15,152 Mortgage banking, net — 61,228 61,228 — 13,737 13,737 Wealth management 165 — 165 188 — 188 Other, net 3,118 1,266 4,384 4,577 (530 ) 4,047 Total noninterest income $ 32,950 $ 62,277 $ 95,227 $ 39,389 $ 14,332 $ 53,721 Wealth Management Segment Service charges on deposit accounts $ 37 $ — $ 37 $ 47 $ — $ 47 Bank card and other fees 14 — 14 43 — 43 Wealth management 15,943 — 15,943 15,037 — 15,037 Other, net 50 22 72 261 55 316 Total noninterest income $ 16,044 $ 22 $ 16,066 $ 15,388 $ 55 $ 15,443 Insurance Segment Insurance commissions $ 23,418 $ — $ 23,418 $ 21,960 $ — $ 21,960 Other, net 64 — 64 6 — 6 Total noninterest income $ 23,482 $ — $ 23,482 $ 21,966 $ — $ 21,966 Consolidated Service charges on deposit accounts $ 16,429 $ — $ 16,429 $ 20,644 $ — $ 20,644 Bank card and other fees 13,289 (217 ) 13,072 14,070 1,125 15,195 Mortgage banking, net — 61,228 61,228 — 13,737 13,737 Insurance commissions 23,418 — 23,418 21,960 — 21,960 Wealth management 16,108 — 16,108 15,225 — 15,225 Other, net 3,232 1,288 4,520 4,844 (475 ) 4,369 Total noninterest income $ 72,476 $ 62,299 $ 134,775 $ 76,743 $ 14,387 $ 91,130 (1) Noninterest income not in scope for FASB ASC Topic 606 includes customer derivatives revenue and miscellaneous credit card fee income within bank card and other fees; mortgage banking, net; amortization of tax credits, accretion of the FDIC indemnification asset, cash surrender value on various life insurance policies, earnings on Trustmark’s non-qualified deferred compensation plans, other partnership investments and rental income within other, net; and security

Defined Benefit and Other Postr

Defined Benefit and Other Postretirement Benefits	6 Months Ended
	Jun. 30, 2020
Compensation And Retirement Disclosure [Abstract]
Defined Benefit and Other Postretirement Benefits	Note 11 – Defined Benefit and Other Postretirement Benefits Qualified Pension Plan Trustmark maintains a noncontributory tax-qualified defined benefit pension plan titled the Trustmark Corporation Pension Plan for Certain Employees of Acquired Financial Institutions (the Continuing Plan) to satisfy commitments made by Trustmark to associates covered through plans obtained in acquisitions. The following table presents information regarding the net periodic benefit cost for the Continuing Plan for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Service cost $ 63 $ 53 $ 127 $ 106 Interest cost 61 90 121 180 Expected return on plan assets (39 ) (50 ) (77 ) (101 ) Recognized net loss due to lump sum settlements 40 63 40 94 Recognized net actuarial loss 82 93 163 186 Net periodic benefit cost $ 207 $ 249 $ 374 $ 465 For the plan year ending December 31, 2020, Trustmark’s minimum required contribution to the Continuing Plan is $306 thousand; however, Management and the Board of Directors of Trustmark will monitor the Continuing Plan throughout 2020 to determine any additional funding requirements by the plan’s measurement date, which is December 31. Supplemental Retirement Plans Trustmark maintains a nonqualified supplemental retirement plan covering key executive officers and senior officers as well as directors who have elected to defer fees. The plan provides for retirement and/or death benefits based on a participant’s covered salary or deferred fees. Although plan benefits may be paid from Trustmark’s general assets, Trustmark has purchased life insurance contracts on the participants covered under the plan, which may be used to fund future benefit payments under the plan. The measurement date for the plan is December 31. As a result of mergers prior to 2014, Trustmark became the administrator of small nonqualified supplemental retirement plans, for which the plan benefits were frozen prior to the merger date. The following table presents information regarding the net periodic benefit cost for Trustmark’s nonqualified supplemental retirement plans for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Service cost $ 20 $ 28 $ 39 $ 55 Interest cost 387 501 801 1,042 Amortization of prior service cost 38 62 75 125 Recognized net actuarial loss 236 154 482 316 Net periodic benefit cost $ 681 $ 745 $ 1,397 $ 1,538

Stock and Incentive Compensatio

Stock and Incentive Compensation	6 Months Ended
	Jun. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock and Incentive Compensation	Note 12 – Stock and Incentive Compensation Trustmark has granted stock and incentive compensation awards and units subject to the provisions of the Stock and Incentive Compensation Plan (the Stock Plan). Current outstanding and future grants of stock and incentive compensation awards are subject to the provisions of the Stock Plan, which is designed to provide flexibility to Trustmark regarding its ability to motivate, attract and retain the services of key associates and directors. The Stock Plan also allows Trustmark to grant nonqualified stock options, incentive stock options, stock appreciation rights, restricted stock, restricted stock units and performance units to key associates and directors. Restricted Stock Grants Performance Awards Trustmark’s performance awards vest over three years and are granted to Trustmark’s executive and senior management teams. Performance awards granted vest based on performance goals of return on average tangible equity and total shareholder return. Performance awards are valued utilizing a Monte Carlo simulation model to estimate fair value of the awards at the grant date. The Monte Carlo simulation was performed by an independent valuation consultant and requires the use of subjective modeling assumptions. These awards are recognized using the straight-line method over the requisite service period. These awards provide for achievement shares if performance measures exceed 100%. The restricted share agreement for these awards provides for voting rights and dividend privileges. During 2020, Trustmark began granting performance units instead of performance awards. The performance units have the same attributes as the previously granted performance awards, except for the performance units do not provide voting rights. Time-Vested Awards Trustmark’s time-vested awards vest over three years and are granted to members of Trustmark’s Board of Directors as well as Trustmark’s executive and senior management teams. Time-vested awards are valued utilizing the fair value of Trustmark’s stock at the grant date. These awards are recognized on the straight-line method over the requisite service period. During 2020, Trustmark began granting time-vested units instead of time-vested awards. The time-vested units have the same attributes as the previously granted time-vested awards, except for the time-vested units do not provide voting rights. The following tables summarize the Stock Plan activity for the periods presented: Three Months Ended June 30, 2020 Performance Awards and Units Time-Vested Awards and Units Nonvested shares, beginning of period 147,533 329,732 Granted — 6,040 Released from restriction — (28,065 ) Forfeited (1,025 ) (3,014 ) Nonvested shares, end of period 146,508 304,693 Six Months Ended June 30, 2020 Performance Awards and Units Time-Vested Awards and Units Nonvested shares, beginning of period 149,914 300,006 Granted 53,450 121,560 Released from restriction (36,357 ) (107,506 ) Forfeited (20,499 ) (9,367 ) Nonvested shares, end of period 146,508 304,693 The following table presents information regarding compensation expense for awards and units under the Stock Plan for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Performance awards and units $ 456 $ 481 $ (57 ) $ 562 Time-vested awards and units 818 798 2,725 1,719 Total compensation expense $ 1,274 $ 1,279 $ 2,668 $ 2,281

Contingencies

Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Contingencies	Note 13 – Contingencies Lending Related Trustmark makes commitments to extend credit and issues standby and commercial letters of credit (letters of credit) in the normal course of business in order to fulfill the financing needs of its customers. The carrying amount of commitments to extend credit and letters of credit approximates the fair value of such financial instruments. Commitments to extend credit are agreements to lend money to customers pursuant to certain specified conditions. Commitments generally have fixed expiration dates or other termination clauses. Because many of these commitments are expected to expire without being fully drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The exposure to credit loss in the event of nonperformance by the other party to the commitments to extend credit is represented by the contract amount of those instruments. Trustmark applies the same credit policies and standards as it does in the lending process when making these commitments. The collateral obtained is based upon the nature of the transaction and the assessed creditworthiness of the borrower. At June 30, 2020 and 2019, Trustmark had unused commitments to extend credit of $4.391 billion and $4.146 billion, respectively. Letters of credit are conditional commitments issued by Trustmark to insure the performance of a customer to a third-party. A financial standby letter of credit irrevocably obligates Trustmark to pay a third-party beneficiary when a customer fails to repay an outstanding loan or debt instrument. A performance standby letter of credit irrevocably obligates Trustmark to pay a third-party beneficiary when a customer fails to perform some contractual, nonfinancial obligation. When issuing letters of credit, Trustmark uses the same policies regarding credit risk and collateral, which are followed in the lending process. At June 30, 2020 and 2019, Trustmark’s maximum exposure to credit loss in the event of nonperformance by the customer for letters of credit was $105.7 million and $103.6 million, respectively. These amounts consist primarily of commitments with maturities of less than three years, which have an immaterial carrying value. Trustmark holds collateral to support standby letters of credit when deemed necessary. As of June 30, 2020 and 2019, the fair value of collateral held was $21.8 million and $30.3 million, respectively. Trustmark adopted FASB ASC Topic 326, effective January 1, 2020, which requires Trustmark to estimate expected credit losses for off-balance sheet credit exposures which are not unconditionally cancellable. Trustmark maintains a separate ACL on off-balance sheet credit exposures, including unfunded loan commitments and letters of credit, which is included on the accompanying consolidated balance sheet as of June 30, 2020 . Expected credit losses for off-balance sheet credit exposures are estimated by calculating a commitment usage factor over the contractual period for exposures that are not unconditionally cancellable by Trustmark. Trustmark generates a loan pool level unfunded amount for the period. Trustmark views the loan pools as either closed-ended or open-ended. Closed-ended loan pools are those that typically fund up to 100% such as other construction and nonowner-occupied. Open-ended loan pools are those that behave similar to a revolver such as the commercial and industrial and home equity line of credit loan pools. In addition to the unfunded balances, Trustmark uses a funding rate for loan pools that are considered open-ended. Trustmark calculates the funding rate of the open-ended loan pools each period. In order to mitigate volatility and incorporate historical experience in the funding rate, Trustmark uses a twelve-quarter moving average. For the closed-ended loan pools, Trustmark takes a conservative approach and uses a 100% funding rate. The funding rate is applied to the pool unfunded commitment balances to ensure that reserves will be applied to the pool as Trustmark believes the pool will reach its historical levels. In addition to the funding rate being applied to the unfunded commitment balance, the total reserve rate is applied. The total reserve rate incorporates both quantitative and qualitative aspects of the current period’s expected credit loss rate. The total reserve rate is loan pool specific and is applied to the unfunded amount to ensure loss factors, both quantitative and qualitative, are being considered on the unfunded portion of the loan pool, consistent with the methodology applied to the funded loan pools. Changes in the ACL on off-balance sheet credit exposures were as follows for the periods presented ($ in thousands): Three Months Ended Six Months Ended June 30, 2020 June 30, 2020 Balance at beginning of period $ 36,421 $ — FASB ASU 2016-13 adoption adjustment — 29,638 Credit loss expense related to off-balance sheet credit exposures 6,242 13,025 Balance at end of period $ 42,663 $ 42,663 Adjustments to the ACL on off-balance sheet credit exposures are recorded to credit loss expense related to off-balance sheet credit exposures in noninterest expense. The increase in the ACL on off-balance sheet credit exposures for the second quarter of 2020 was primarily due to net changes in the economic forecast due to the negative effects of the COVID-19 pandemic on the overall economy and macroeconomic factors used in the quantitative calculation of the ACL. No credit loss estimate is reported for off-balance sheet credit exposures that are unconditionally cancellable by Trustmark or for undrawn amounts under such arrangements that may be drawn prior to the cancellation of the arrangement. Legal Proceedings Trustmark’s wholly-owned subsidiary, TNB, has been named as a defendant in several lawsuits related to the collapse of the Stanford Financial Group. On August 23, 2009, a purported class action complaint was filed in the District Court of Harris County, Texas, by Peggy Roif Rotstain, Guthrie Abbott, Catherine Burnell, Steven Queyrouze, Jaime Alexis Arroyo Bornstein and Juan C. Olano (collectively, Class Plaintiffs), on behalf of themselves and all others similarly situated, naming TNB and four other financial institutions and one individual, each of which are unaffiliated with Trustmark, as defendants. The complaint seeks to recover (i) alleged fraudulent transfers from each of the defendants in the amount of fees and other monies received by each defendant from entities controlled by R. Allen Stanford (collectively, the Stanford Financial Group) and (ii) damages allegedly attributable to alleged conspiracies by one or more of the defendants with the Stanford Financial Group to commit fraud and/or aid and abet fraud on the asserted grounds that defendants knew or should have known the Stanford Financial Group was conducting an illegal and fraudulent scheme. Class Plaintiffs have demanded a jury trial. Class Plaintiffs did not quantify damages. In November 2009, the lawsuit was removed to federal court by certain defendants and then transferred by the United States Panel on Multidistrict Litigation to federal court in the Northern District of Texas (Dallas) where multiple Stanford related matters are being consolidated for pre-trial proceedings. In May 2010, all defendants (including TNB) filed motions to dismiss the lawsuit. In August 2010, the court authorized and approved the formation of an Official Stanford Investors Committee (OSIC) to represent the interests of Stanford investors and, under certain circumstances, to file legal actions for the benefit of Stanford investors. In December 2011, the OSIC filed a motion to intervene in this action. In September 2012, the district court referred the case to a magistrate judge for hearing and determination of certain pretrial issues. In December 2012, the court granted the OSIC’s motion to intervene, and the OSIC filed an Intervenor Complaint against one of the other defendant financial institutions. In February 2013, the OSIC filed a second Intervenor Complaint that asserts claims against TNB and the remaining defendant financial institutions. The OSIC seeks to recover: (i) alleged fraudulent transfers in the amount of the fees each of the defendants allegedly received from Stanford Financial Group, the profits each of the defendants allegedly made from Stanford Financial Group deposits, and other monies each of the defendants allegedly received from Stanford Financial Group; (ii) damages attributable to alleged conspiracies by each of the defendants with the Stanford Financial Group to commit fraud and/or aid and abet fraud and conversion on the asserted grounds that the defendants knew or should have known the Stanford Financial Group was conducting an illegal and fraudulent scheme; and (iii) punitive damages. The OSIC did not quantify damages. In July 2013, all defendants (including TNB) filed motions to dismiss the OSIC’s claims. In March 2015, the court entered an order authorizing the parties to conduct discovery regarding class certification, staying all other discovery and setting a deadline for the parties to complete briefing on class certification issues. In April 2015, the court granted in part and denied in part the defendants’ motions to dismiss the Class Plaintiffs’ claims and the OSIC’s claims. The court dismissed all of the Class Plaintiffs’ fraudulent transfer claims and dismissed certain of the OSIC’s claims. The court denied the motions by TNB and the other financial institution defendants to dismiss the OSIC’s constructive fraudulent transfer claims. On June 23, 2015, the court allowed the Class Plaintiffs to file a Second Amended Class Action Complaint (SAC), which asserted new claims against TNB and certain of the other defendants for (i) aiding, abetting and participating in a fraudulent scheme, (ii) aiding, abetting and participating in violations of the Texas Securities Act, (iii) aiding, abetting and participating in breaches of fiduciary duty, (iv) aiding, abetting and participating in conversion and (v) conspiracy. On July 14, 2015, the defendants (including TNB) filed motions to dismiss the SAC and to reconsider the court’s prior denial to dismiss the OSIC’s constructive fraudulent transfer claims against TNB and the other financial institutions that are defendants in the action. On July 27, 2016, the court denied the motion by TNB and the other financial institution defendants to dismiss the SAC and also denied the motion by TNB and the other financial institution defendants to reconsider the court’s prior denial to dismiss the OSIC’s constructive fraudulent transfer claims. On August 24, 2016, TNB filed its answer to the SAC. On October 20, 2017, the OSIC filed a motion seeking an order lifting the discovery stay and establishing a trial schedule. On November 4, 2016, the OSIC filed a First Amended Intervenor Complaint, which added claims for (i) aiding, abetting or participation in violations of the Texas Securities Act and (ii) aiding, abetting or participation in the breach of fiduciary duty. On November 7, 2017, the court denied the Class Plaintiffs’ motion seeking class certification and designation of class representatives and counsel, finding that common issues of fact did not predominate. The court granted the OSIC’s motion to lift the discovery stay that it had previously ordered. On May 3, 2019, individual investors and entities filed motions to intervene in the action. On September 18, 2019, the court denied the motions to intervene. On October 14, 2019, certain of the proposed intervenors filed a notice of appeal. On December 14, 2009, a different Stanford-related lawsuit was filed in the District Court of Ascension Parish, Louisiana, individually by Harold Jackson, Paul Blaine and Carolyn Bass Smith, Christine Nichols, and Ronald and Ramona Hebert naming TNB (misnamed as Trust National Bank) and other individuals and entities not affiliated with Trustmark as defendants. The complaint seeks to recover the money lost by these individual plaintiffs as a result of the collapse of the Stanford Financial Group (in addition to other damages) under various theories and causes of action, including negligence, breach of contract, breach of fiduciary duty, negligent misrepresentation, detrimental reliance, conspiracy, and violation of Louisiana’s uniform fiduciary, securities, and racketeering laws. The complaint does not quantify the amount of money the plaintiffs seek to recover. In January 2010, the lawsuit was removed to federal court by certain defendants and then transferred by the United States Panel on Multidistrict Litigation to federal court in the Northern District of Texas (Dallas) where multiple Stanford related matters are being consolidated for pre-trial proceedings. On March 29, 2010, the court stayed the case. TNB filed a motion to lift the stay, which was denied on February 28, 2012. In September 2012, the district court referred the case to a magistrate judge for hearing and determination of certain pretrial issues. On April 11, 2016, Trustmark learned that a different Stanford-related lawsuit had been filed on that date in the Superior Court of Justice in Ontario, Canada, by The Toronto-Dominion Bank (“TD Bank”), naming TNB and three other financial institutions not affiliated with Trustmark as defendants. The complaint seeks a declaration specifying the degree to which each of TNB and the other defendants are liable in respect of any loss and damage for which TD Bank is found to be liable in a litigation commenced against TD Bank brought by the Joint Liquidators of Stanford International Bank Limited in the Superior Court of Justice, Commercial List in Ontario, Canada (the “Joint Liquidators’ Action”), as well as contribution and indemnity in respect of any judgment, interest and costs TD Bank is ordered to pay in the Joint Liquidators’ Action. To date, TNB has not been served in connection with this action. On November 1, 2019, TNB was named as a defendant in a complaint filed by Paul Blaine Smith, Carolyn Bass Smith and other plaintiffs identified therein (the Smith Complaint). The Smith Complaint was filed in District Court, Harris County, Texas and named TNB and four other financial institutions and one individual, each of which are unaffiliated with Trustmark, as defendants. The Smith Complaint relates to the collapse of the Stanford Financial Group, as does the other pending litigation relating to Stanford summarized above. Plaintiffs in the Smith Complaint have demanded a jury trial. On January 15, 2020, the court granted Stanford Financial Group receiver’s motion to stay the state court action. On February 26, 2020, the lawsuit was removed to federal court in the Southern District of Texas by TNB. Trustmark and its counsel are carefully evaluating the Smith Complaint in the form that is publicly available, and will update the foregoing description to the extent that additional material facts are ascertained. TNB’s relationship with the Stanford Financial Group began as a result of Trustmark’s acquisition of a Houston-based bank in August 2006, and consisted of correspondent banking and other traditional banking services in the ordinary course of business. All Stanford-related lawsuits are in pre-trial stages. On December 30, 2019, a complaint was filed in the United States District Court for the Southern District of Mississippi, Northern Division (the Court) by Alysson Mills in her capacity as Court-appointed Receiver (the Receiver) for Arthur Lamar Adams (Adams) and Madison Timber Properties, LLC (Madison Timber), naming TNB, two other Mississippi-based financial institutions both of which are unaffiliated with Trustmark and two individuals, one of who was employed by TNB at all times relevant to the complaint and the other was employed either by TNB or one of the other defendant financial institutions, as defendants. The complaint seeks to recover from the defendants, for the benefit of the receivership estate and also for certain investors who were allegedly defrauded by Adams and Madison Timber, damages (including punitive damages) and related costs allegedly attributable to actions of the defendants that allegedly enabled illegal and fraudulent activities engaged in by Adams and Madison Timber. The Receiver did not quantify damages. TNB’s relationship with Adams and Madison Timber consisted of traditional banking services in the ordinary course of business. Trustmark and its subsidiaries are also parties to other lawsuits and other claims that arise in the ordinary course of business. Some of the lawsuits assert claims related to the lending, collection, servicing, investment, trust and other business activities, and some of the lawsuits allege substantial claims for damages. All pending legal proceedings described above are being vigorously contested. In accordance with FASB ASC Subtopic 450-20, “Loss Contingencies,” Trustmark will establish an accrued liability for litigation matters when those matters present loss contingencies that are both probable and reasonably estimable. At the present time, Trustmark believes, based on its evaluation and the advice of legal counsel, that a loss in any such proceeding is not probable and a reasonable estimate cannot reasonably be made.

Earnings Per Share (EPS)

Earnings Per Share (EPS)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share (EPS)	Note 14 – Earnings Per Share (EPS) The following table reflects weighted-average shares used to calculate basic and diluted EPS for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Basic shares 63,416 64,678 63,586 64,957 Dilutive shares 139 137 136 132 Diluted shares 63,555 64,815 63,722 65,089 Weighted-average antidilutive stock awards were excluded in determining diluted EPS. The following table reflects weighted-average antidilutive stock awards for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Weighted-average antidilutive stock awards 11 23 63 78

Statements of Cash Flows

Statements of Cash Flows	6 Months Ended
	Jun. 30, 2020
Supplemental Cash Flow Information [Abstract]
Statements of Cash Flows	Note 15 – Statements of Cash Flows The following table reflects specific transaction amounts for the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Income taxes paid $ 23,309 $ 5,336 Interest expense paid on deposits and borrowings 26,808 43,004 Noncash transfers from loans to other real estate 406 2,101 Finance right-of-use assets resulting from lease liabilities — 10,698 Operating right-of-use assets resulting from lease liabilities 671 32,762

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2020
Stockholders Equity Note [Abstract]
Shareholders' Equity	Note 16 – Shareholders’ Equity Regulatory Capital Trustmark and TNB are subject to minimum risk-based capital and leverage capital requirements, as described in the section captioned “Capital Adequacy” included in Part I. Item 1. – Business of Trustmark’s 2019 Annual Report, which are administered by the federal bank regulatory agencies. These capital requirements, as defined by federal regulations, involve quantitative and qualitative measures of assets, liabilities and certain off-balance sheet instruments. Trustmark’s and TNB’s minimum risk-based capital requirements include a capital conservation buffer of 2.50% at June 30, 2020 and December 31, 2019. Accumulated other comprehensive income (loss), net of tax, is not included in computing regulatory capital. Trustmark has elected the five-year phase-in transition period related to adopting FASB ASU 2016-13 for regulatory capital purposes. Failure to meet minimum capital requirements can result in certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the financial statements of Trustmark and TNB and limit Trustmark’s and TNB’s ability to pay dividends. As of June 30, 2020, Trustmark and TNB exceeded all applicable minimum capital standards. In addition, Trustmark and TNB met applicable regulatory guidelines to be considered well-capitalized at June 30, 2020. To be categorized in this manner, Trustmark and TNB maintained minimum common equity Tier 1 risk-based capital, Tier 1 risk-based capital, total risk-based capital and Tier 1 leverage ratios as set forth in the accompanying table, and were not subject to any written agreement, order or capital directive, or prompt corrective action directive issued by their primary federal regulators to meet and maintain a specific capital level for any capital measures. There are no significant conditions or events that have occurred since June 30, 2020, which Management believes have affected Trustmark’s or TNB’s present classification. The following table provides Trustmark’s and TNB’s actual regulatory capital amounts and ratios under regulatory capital standards in effect at June 30, 2020 and December 31, 2019 ($ in thousands): Actual Regulatory Capital Minimum To Be Well Amount Ratio Requirement Capitalized At June 30, 2020: Common Equity Tier 1 Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,317,378 11.42 % 7.00 % n/a Trustmark National Bank 1,353,727 11.73 % 7.00 % 6.50 % Tier 1 Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,377,378 11.94 % 8.50 % n/a Trustmark National Bank 1,353,727 11.73 % 8.50 % 8.00 % Total Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,499,887 13.00 % 10.50 % n/a Trustmark National Bank 1,476,236 12.80 % 10.50 % 10.00 % Tier 1 Leverage (to Average Assets) Trustmark Corporation $ 1,377,378 9.08 % 4.00 % n/a Trustmark National Bank 1,353,727 8.94 % 4.00 % 5.00 % At December 31, 2019: Common Equity Tier 1 Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,312,668 11.93 % 7.00 % n/a Trustmark National Bank 1,352,893 12.30 % 7.00 % 6.50 % Tier 1 Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,372,668 12.48 % 8.50 % n/a Trustmark National Bank 1,352,893 12.30 % 8.50 % 8.00 % Total Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,457,760 13.25 % 10.50 % n/a Trustmark National Bank 1,437,985 13.07 % 10.50 % 10.00 % Tier 1 Leverage (to Average Assets) Trustmark Corporation $ 1,372,668 10.48 % 4.00 % n/a Trustmark National Bank 1,352,893 10.35 % 4.00 % 5.00 % Stock Repurchase Program On March 11, 2016, the Board of Directors of Trustmark authorized a stock repurchase program under which $100.0 million of Trustmark’s outstanding common stock could be acquired through March 31, 2019. Trustmark repurchased approximately 1.2 million shares of its common stock valued at $36.9 million during the three months ended March 31, 2019. Under this authority, Trustmark repurchased approximately 3.2 million shares valued at $100.0 million. On April 1, 2019, the Board of Directors of Trustmark authorized a stock repurchase program under which $100.0 million of Trustmark’s outstanding common stock could be acquired through March 31, 2020. Trustmark repurchased approximately 887 thousand shares of its common stock valued at $27.5 million during the three months ended March 31, 2020. Under this authority, Trustmark repurchased approximately 1.5 million shares valued at $47.2 million. On January 28, 2020, the Board of Directors of Trustmark authorized a new stock repurchase program, effective April 1, 2020, under which $100.0 million of Trustmark’s outstanding common stock may be acquired through December 31, 2021. The shares may be purchased from time to time at prevailing market prices, through open market or private transactions, depending on market conditions. There is no guarantee as to the number of shares that may be repurchased by Trustmark, and Trustmark may discontinue purchases under the program at any time at Management’s discretion. On March 9, 2020, Trustmark suspended its share repurchase program s to preserve capital to support customers during the COVID-19 pandemic. Other Comprehensive Income (Loss) and Accumulated Other Comprehensive Income (Loss) The following tables present the net change in the components of accumulated other comprehensive income (loss) and the related tax effects allocated to each component for the periods presented ($ in thousands). The amortization of prior service cost, recognized net loss due to lump sum settlements and change in net actuarial loss are included in the computation of net periodic benefit cost (see Note 11 – Defined Benefit and Other Postretirement Benefits for additional details). Reclassification adjustments related to pension and other postretirement benefit plans are included in salaries and employee benefits and other expense in the accompanying consolidated statements of income. Reclassification adjustments related to the cash flow hedge derivative are included in other interest expense in the accompanying consolidated statements of income. Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Before Tax Amount Tax (Expense) Benefit Net of Tax Amount Before Tax Amount Tax (Expense) Benefit Net of Tax Amount Securities available for sale and transferred securities: Net unrealized holding gains (losses) arising during the period $ 2,648 $ (662 ) $ 1,986 $ 20,079 $ (5,020 ) $ 15,059 Change in net unrealized holding loss on securities transferred to held to maturity 778 (195 ) 583 1,256 (314 ) 942 Total securities available for sale and transferred securities 3,426 (857 ) 2,569 21,335 (5,334 ) 16,001 Pension and other postretirement benefit plans: Reclassification adjustments for changes realized in net income: Net change in prior service costs 38 (10 ) 28 62 (15 ) 47 Recognized net loss due to lump sum settlements 40 (10 ) 30 63 (16 ) 47 Change in net actuarial loss 318 (78 ) 240 247 (61 ) 186 Total pension and other postretirement benefit plans 396 (98 ) 298 372 (92 ) 280 Cash flow hedge derivatives: Change in accumulated gain (loss) on effective cash flow hedge derivatives — — — (101 ) 25 (76 ) Reclassification adjustment for (gain) loss realized in net income — — — (141 ) 35 (106 ) Total cash flow hedge derivatives — — — (242 ) 60 (182 ) Total other comprehensive income (loss) $ 3,822 $ (955 ) $ 2,867 $ 21,465 $ (5,366 ) $ 16,099 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Before Tax Amount Tax (Expense) Benefit Net of Tax Amount Before Tax Amount Tax (Expense) Benefit Net of Tax Amount Securities available for sale and transferred securities: Net unrealized holding gains (losses) arising during the period $ 43,155 $ (10,789 ) $ 32,366 $ 38,903 $ (9,726 ) $ 29,177 Change in net unrealized holding loss on securities transferred to held to maturity 1,639 (410 ) 1,229 2,003 (501 ) 1,502 Total securities available for sale and transferred securities 44,794 (11,199 ) 33,595 40,906 (10,227 ) 30,679 Pension and other postretirement benefit plans: Reclassification adjustments for changes realized in net income: Net change in prior service costs 75 (19 ) 56 125 (31 ) 94 Recognized net loss due to lump sum settlements 40 (10 ) 30 94 (23 ) 71 Change in net actuarial loss 645 (161 ) 484 502 (126 ) 376 Total pension and other postretirement benefit plans 760 (190 ) 570 721 (180 ) 541 Cash flow hedge derivatives: Change in accumulated gain (loss) on effective cash flow hedge derivatives — — — (164 ) 41 (123 ) Reclassification adjustment for (gain) loss realized in net income — — — (312 ) 78 (234 ) Total cash flow hedge derivatives — — — (476 ) 119 (357 ) Total other comprehensive income (loss) $ 45,554 $ (11,389 ) $ 34,165 $ 41,151 $ (10,288 ) $ 30,863 The following table presents the changes in the balances of each component of accumulated other comprehensive income (loss) for the periods presented ($ in thousands). All amounts are presented net of tax. Securities Available and Transferred Securities Defined Benefit Pension Items Cash Flow Hedge Derivatives Total Balance at January 1, 2020 $ (8,017 ) $ (15,583 ) $ — $ (23,600 ) Other comprehensive income (loss) before reclassification 33,595 — — 33,595 Amounts reclassified from accumulated other comprehensive income (loss) — 570 — 570 Net other comprehensive income (loss) 33,595 570 — 34,165 Balance at June 30, 2020 $ 25,578 $ (15,013 ) $ — $ 10,565 Balance at January 1, 2019 $ (43,824 ) $ (12,324 ) $ 469 $ (55,679 ) Other comprehensive income (loss) before reclassification 30,679 — (123 ) 30,556 Amounts reclassified from accumulated other comprehensive income (loss) — 541 (234 ) 307 Net other comprehensive income (loss) 30,679 541 (357 ) 30,863 Balance at June 30, 2019 $ (13,145 ) $ (11,783 ) $ 112 $ (24,816 )

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value	Note 17 – Fair Value Financial Instruments Measured at Fair Value The methodologies Trustmark uses in determining the fair values are based primarily on the use of independent, market-based data to reflect a value that would be reasonably expected upon exchange of the position in an orderly transaction between market participants at the measurement date. The predominant portion of assets that are stated at fair value are of a nature that can be valued using prices or inputs that are readily observable through a variety of independent data providers. The providers selected by Trustmark for fair valuation data are widely recognized and accepted vendors whose evaluations support the pricing functions of financial institutions, investment and mutual funds, and portfolio managers. Trustmark has documented and evaluated the pricing methodologies used by the vendors and maintains internal processes that regularly test valuations for anomalies. Trustmark utilizes an independent pricing service to advise it on the carrying value of the securities available for sale portfolio. As part of Trustmark’s procedures, the price provided from the service is evaluated for reasonableness given market changes. When a questionable price exists, Trustmark investigates further to determine if the price is valid. If needed, other market participants may be utilized to determine the correct fair value. Trustmark has also reviewed and confirmed its determinations in thorough discussions with the pricing source regarding their methods of price discovery. Mortgage loan commitments are valued based on the securities prices of similar collateral, term, rate and delivery for which the loan is eligible to deliver in place of the particular security. Trustmark acquires a broad array of mortgage security prices that are supplied by a market data vendor, which in turn accumulates prices from a broad list of securities dealers. Prices are processed through a mortgage pipeline management system that accumulates and segregates all loan commitment and forward-sale transactions according to the similarity of various characteristics (maturity, term, rate, and collateral). Prices are matched to those positions that are deemed to be an eligible substitute or offset ( i.e Trustmark estimates fair value of the MSR through the use of prevailing market participant assumptions and market participant valuation processes. This valuation is periodically tested and validated against other third-party firm valuations. Trustmark obtains the fair value of interest rate swaps from a third-party pricing service that uses an industry standard discounted cash flow methodology. In addition, credit valuation adjustments are incorporated in the fair values to account for potential nonperformance risk. In adjusting the fair value of its interest rate swap contracts for the effect of nonperformance risk, Trustmark has considered any applicable credit enhancements such as collateral postings, thresholds, mutual puts, and guarantees. In conjunction with the FASB’s fair value measurement guidance, Trustmark made an accounting policy election to measure the credit risk of these derivative financial instruments, which are subject to master netting agreements, on a net basis by counterparty portfolio. Trustmark has determined that the majority of the inputs used to value its interest rate swaps offered to qualified commercial borrowers fall within Level 2 of the fair value hierarchy, while the credit valuation adjustments associated with these derivatives utilize Level 3 inputs, such as estimates of current credit spreads. Trustmark has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its interest rate swaps and has determined that the credit valuation adjustment is not significant to the overall valuation of these derivatives. As a result, Trustmark classifies its interest rate swap valuations in Level 2 of the fair value hierarchy. Trustmark also utilizes exchange-traded derivative instruments such as Treasury note futures contracts and option contracts to achieve a fair value return that offsets the changes in fair value of the MSR attributable to interest rates. Fair values of these derivative instruments are determined from quoted prices in active markets for identical assets therefore allowing them to be classified within Level 1 of the fair value hierarchy. In addition, Trustmark utilizes derivative instruments such as interest rate lock commitments in its mortgage banking area which lack observable inputs for valuation purposes resulting in their inclusion in Level 3 of the fair value hierarchy. At this time, Trustmark presents no fair values that are derived through internal modeling. Should positions requiring fair valuation arise that are not relevant to existing methodologies, Trustmark will make every reasonable effort to obtain market participant assumptions, or independent evaluation. Financial Assets and Liabilities The following tables summarize financial assets and financial liabilities measured at fair value on a recurring basis as of June 30, 2020 and December 31, 2019, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value ($ in thousands). There were no transfers between fair value levels for the six months ended June 30, 2020 and the year ended December 31, 2019. June 30, 2020 Total Level 1 Level 2 Level 3 U.S. Government agency obligations $ 19,898 $ — $ 19,898 $ — Obligations of states and political subdivisions 11,176 — 11,176 — Mortgage-backed securities 1,853,079 — 1,853,079 — Securities available for sale 1,884,153 — 1,884,153 — Loans held for sale 355,089 — 355,089 — Mortgage servicing rights 57,811 — — 57,811 Other assets - derivatives 58,880 843 43,707 14,330 Other liabilities - derivatives 4,994 335 4,659 — December 31, 2019 Total Level 1 Level 2 Level 3 U.S. Government agency obligations $ 22,327 $ — $ 22,327 $ — Obligations of states and political subdivisions 25,465 — 25,465 — Mortgage-backed securities 1,554,612 — 1,554,612 — Securities available for sale 1,602,404 — 1,602,404 — Loans held for sale 226,347 — 226,347 — Mortgage servicing rights 79,394 — — 79,394 Other assets - derivatives 17,956 244 16,273 1,439 Other liabilities - derivatives 6,063 4,414 1,649 — The changes in Level 3 assets measured at fair value on a recurring basis for the six months ended June 30, 2020 and 2019 are summarized as follows ($ in thousands): MSR Other Assets - Derivatives Balance, January 1, 2020 $ 79,394 $ 1,439 Total net (loss) gain included in Mortgage banking, net (1) (33,979 ) 22,382 Additions 12,396 — Sales — (9,491 ) Balance, June 30, 2020 $ 57,811 $ 14,330 The amount of total gains (losses) for the period included in earnings that are attributable to the change in unrealized gains or losses still held at June 30, 2020 $ (27,158 ) $ 12,897 Balance, January 1, 2019 $ 95,596 $ 1,187 Total net (loss) gain included in Mortgage banking, net (1) (22,388 ) 3,889 Additions 6,075 — Sales — (2,531 ) Balance, June 30, 2019 $ 79,283 $ 2,545 The amount of total gains (losses) for the period included in earnings that are attributable to the change in unrealized gains or losses still held at June 30, 2019 $ (17,072 ) $ 678 (1) Total net (loss) gain included in Mortgage banking, net relating to the MSR includes changes in fair value due to market changes and due to run-off. Trustmark may be required, from time to time, to measure certain assets at fair value on a nonrecurring basis in accordance with GAAP. Assets at June 30, 2020, which have been measured at fair value on a nonrecurring basis, include collateral-dependent LHFI. A loan is collateral dependent when the borrower is experiencing financial difficulty and repayment of the loan is expected to be provided substantially through the sale of the collateral. The expected credit loss for collateral-dependent loans is measured as the difference between the amortized cost basis of the loan and the fair value of the collateral, adjusted for the estimated cost to sell. Fair value estimates for collateral-dependent loans are derived from appraised values based on the current market value or as is value of the collateral, normally from recently received and reviewed appraisals. Current appraisals are ordered on an annual basis based on the inspection date or more often if market conditions necessitate. Appraisals are obtained from state-certified appraisers and are based on certain assumptions, which may include construction or development status and the highest and best use of the property. These appraisals are reviewed by Trustmark’s Appraisal Review Department to ensure they are acceptable, and values are adjusted down for costs associated with asset disposal. At June 30, 2020, Trustmark had outstanding balances of $42.1 million with a related ACL of $2.3 million in collateral-dependent LHFI. At December 31, 2019, Trustmark had outstanding balances of $41.2 million with a related allowance of $5.5 million in impaired LHFI that were individually evaluated for impairment and written down to the fair value of the underlying collateral less cost to sell based on the fair value of the collateral or other unobservable input compared. Both the collateral-dependent LHFI and the individually evaluated impaired LHFI are classified as Level 3 in the fair value hierarchy. Nonfinancial Assets and Liabilities Certain nonfinancial assets measured at fair value on a nonrecurring basis include foreclosed assets (upon initial recognition or subsequent impairment), nonfinancial assets and nonfinancial liabilities measured at fair value in the second step of a goodwill impairment test, and intangible assets and other nonfinancial long-lived assets measured at fair value for impairment assessment. Other real estate includes assets that have been acquired in satisfaction of debt through foreclosure and is carried at the lower of cost or estimated fair value. Fair value is based on independent appraisals and other relevant factors. In the determination of fair value subsequent to foreclosure, Management also considers other factors or recent developments, such as changes in market conditions from the time of valuation and anticipated sales values considering plans for disposition, which could result in an adjustment to lower the collateral value estimates indicated in the appraisals. Periodic revaluations are classified as Level 3 in the fair value hierarchy since assumptions are used that may not be observable in the market. Foreclosed assets of $3.2 million were remeasured during the first six months of 2020, requiring write-downs of $873 thousand to reach their current fair values compared to $8.8 million of foreclosed assets that were remeasured during the first six months of 2019, requiring write-downs of $1.1 million. Fair Value of Financial Instruments FASB ASC Topic 825, “Financial Instruments,” requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis. The carrying amounts and estimated fair values of financial instruments at June 30, 2020 and December 31, 2019, are as follows ($ in thousands): June 30, 2020 December 31, 2019 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Financial Assets: Level 2 Inputs: Cash and short-term investments $ 1,026,640 $ 1,026,640 $ 358,916 $ 358,916 Securities held to maturity 660,048 690,561 738,099 746,202 Level 3 Inputs: Net LHFI and PPP loans 10,480,401 10,500,218 9,251,351 9,235,674 Net acquired loans (1) — — 71,786 71,786 Financial Liabilities: Level 2 Inputs: Deposits 13,505,473 13,512,248 11,245,557 11,250,071 Federal funds purchased and securities sold under repurchase agreements 70,255 70,255 256,020 256,020 Other borrowings 152,860 152,861 85,396 85,374 Junior subordinated debt securities 61,856 45,155 61,856 50,722 (1) Upon adoption of FASB ASC Topic 326 at January 1, 2020, Trustmark elected to account for its existing acquired loans as purchased credit deteriorated loans included within the LHFI portfolio. See Note 4 – Acquired Loans for additional details. Fair Value Option Trustmark has elected to account for its mortgage LHFS under the fair value option, with interest income on these mortgage LHFS reported in interest and fees on LHFS and LHFI. The fair value of the mortgage LHFS is determined using quoted prices for a similar asset, adjusted for specific attributes of that loan. The mortgage LHFS are actively managed and monitored and certain market risks of the loans may be mitigated through the use of derivatives. These derivative instruments are carried at fair value with changes in fair value recorded as noninterest income in mortgage banking, net. The changes in the fair value of LHFS are largely offset by changes in the fair value of the derivative instruments. For the three and six months ended June 30, 2020, a net loss of $445 thousand and a net gain of $7.3 million, respectively, was recorded as noninterest income in mortgage banking, net for changes in the fair value of LHFS accounted for under the fair value option, compared to net gains of $2.2 million and $2.9 million for the three and six months ended June 30, 2019, respectively. Interest and fees on LHFS and LHFI for the three and six months ended June 30, 2020 included $1.5 million and $2.8 million, respectively, of interest earned on LHFS accounted for under the fair value option, compared to $1.3 million and $2.4 million for the three and six months ended June 30, 2019, respectively. Election of the fair value option allows Trustmark to reduce the accounting volatility that would otherwise result from the asymmetry created by accounting for the financial instruments at the lower of cost or fair value and the derivatives at fair value. The fair value option election does not apply to GNMA optional repurchase loans which do not meet the requirements under FASB ASC Topic 825 to be accounted for under the fair value option. GNMA optional repurchase loans totaled $121.4 million and $57.1 million at June 30, 2020 and December 31, 2019, respectively, and are included in LHFS on the accompanying consolidated balance sheets. For additional information regarding GNMA optional repurchase loans, please see the section captioned “Past Due LHFS” included in Note 3 – LHFI and Allowance for Credit Losses, LHFI. The following table provides information about the fair value and the contractual principal outstanding of LHFS accounted for under the fair value option as of June 30, 2020 and December 31, 2019 ($ in thousands): June 30, 2020 December 31, 2019 Fair value of LHFS $ 233,687 $ 169,285 LHFS contractual principal outstanding 221,365 164,420 Fair value less unpaid principal $ 12,322 $ 4,865

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Note 18 – Derivative Financial Instruments Derivatives Designated as Hedging Instruments On April 4, 2013, Trustmark entered into a forward interest rate swap contract on junior subordinated debentures with a total notional amount of $60.0 million. The interest rate swap contract was designated as a derivative instrument in a cash flow hedge under FASB ASC Topic 815, “Derivatives and Hedging,” with the objective of protecting the quarterly interest payments on Trustmark’s $60.0 million of junior subordinated debentures issued to Trustmark Preferred Capital Trust I throughout the five-year The interest rate swap matured on December 31, 2019; therefore, there was no accumulated net after-tax amount related to the effective cash flow hedge included in accumulated other comprehensive income (loss) at December 31, 2019. No ineffectiveness related to the interest rate swap designated as a cash flow hedge was recognized in the consolidated statements of income for the six months ended June 30, 2019. Amounts reported in accumulated other comprehensive income (loss) related to this derivative were reclassified to other interest expense as interest payments were made on Trustmark’s variable rate junior subordinated debentures. Derivatives not Designated as Hedging Instruments Trustmark utilizes a portfolio of exchange-traded derivative instruments, such as Treasury note futures contracts and option contracts, to achieve a fair value return that economically hedges changes in the fair value of the MSR attributable to interest rates. These transactions are considered freestanding derivatives that do not otherwise qualify for hedge accounting. The total notional amount of these derivative instruments was $385.0 million at June 30, 2020 compared to $564.0 million at December 31, 2019. Changes in the fair value of these exchange-traded derivative instruments are recorded as noninterest income in mortgage banking, net and are offset by changes in the fair value of the MSR. The impact of this strategy resulted in a net negative ineffectiveness of $2.0 million and $53 thousand for the three months ended June 30, 2020 and 2019, respectively. For the six months ended June 30, 2020 and 2019, the impact was a net positive ineffectiveness of $7.9 million and a net negative ineffectiveness of $4.8 million, respectively. As part of Trustmark’s risk management strategy in the mortgage banking area, derivative instruments such as forward sales contracts are utilized. Trustmark’s obligations under forward sales contracts consist of commitments to deliver mortgage loans, originated and/or purchased, in the secondary market at a future date. Changes in the fair value of these derivative instruments are recorded as noninterest income in mortgage banking, net and are offset by changes in the fair value of LHFS. Trustmark’s off-balance sheet obligations under these derivative instruments totaled $359.5 million at June 30, 2020, with a negative valuation adjustment of $2.6 million, compared to $209.0 million, with a negative valuation adjustment of $486 thousand, at December 31, 2019. Trustmark also utilizes derivative instruments such as interest rate lock commitments in its mortgage banking area. Interest rate lock commitments are residential mortgage loan commitments with customers, which guarantee a specified interest rate for a specified time period. Changes in the fair value of these derivative instruments are recorded as noninterest income in mortgage banking, net and are offset by the changes in the fair value of forward sales contracts. Trustmark’s off-balance sheet obligations under these derivative instruments totaled $427.3 million at June 30, 2020, with a positive valuation adjustment of $14.3 million, compared to $92.1 million, with a positive valuation adjustment of $1.4 million, as of December 31, 2019. Trustmark offers certain derivatives products directly to qualified commercial lending clients seeking to manage their interest rate risk. Trustmark economically hedges interest rate swap transactions executed with commercial lending clients by entering into offsetting interest rate swap transactions with institutional derivatives market participants. Derivatives transactions executed as part of this program are not designated as qualifying hedging relationships and are, therefore, carried at fair value with the change in fair value recorded as noninterest income in bank card and other fees. Because these derivatives have mirror-image contractual terms, in addition to collateral provisions which mitigate the impact of nonperformance risk, the changes in fair value are expected to substantially offset. As of June 30, 2020, Trustmark had interest rate swaps with an aggregate notional amount of $978.1 million related to this program, compared to $893.1 million as of December 31, 2019. Credit-risk-related Contingent Features Trustmark has agreements with its financial institution counterparties that contain provisions where if Trustmark defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then Trustmark could also be declared in default on its derivatives obligations. As of June 30, 2020 and December 31, 2019, the termination value of interest rate swaps in a liability position, which includes accrued interest but excludes any adjustment for nonperformance risk, related to these agreements was $1.9 million and $1.0 million, respectively. As of June 30, 2020, Trustmark had posted collateral of $2.1 million against its obligations because of negotiated thresholds and minimum transfer amounts under these agreements. If Trustmark had breached any of these triggering provisions at June 30, 2020, it could have been required to settle its obligations under the agreements at the termination value. Credit risk participation agreements arise when Trustmark contracts with other financial institutions, as a guarantor or beneficiary, to share credit risk associated with certain interest rate swaps. These agreements provide for reimbursement of losses resulting from a third-party default on the underlying swap. At both June 30, 2020 and December 31, 2019, Trustmark had entered into three risk participation agreements as a beneficiary with an aggregate notional amount of $41.7 million and $37.6 million, respectively. At both June 30, 2020 and December 31, 2019, Trustmark had entered into ten risk participation agreements as a guarantor with an aggregate notional amount of $73.4 million and $79.3 million, respectively. The aggregate fair values of these risk participation agreements were immaterial at both June 30, 2020 and December 31, 2019. Tabular Disclosures The following tables disclose the fair value of derivative instruments in Trustmark’s consolidated balance sheets as of June 30, 2020 and December 31, 2019 as well as the effect of these derivative instruments on Trustmark’s results of operations for the periods presented ($ in thousands): June 30, 2020 December 31, 2019 Derivatives not designated as hedging instruments Interest rate contracts: Futures contracts included in other assets $ 509 $ — Exchange traded purchased options included in other assets 334 244 OTC written options (rate locks) included in other assets 14,330 1,439 Interest rate swaps included in other assets 43,579 16,209 Credit risk participation agreements included in other assets 128 64 Futures contracts included in other liabilities — 2,654 Forward contracts included in other liabilities 2,574 486 Exchange traded written options included in other liabilities 335 1,760 Interest rate swaps included in other liabilities 1,932 1,122 Credit risk participation agreements included in other liabilities 153 41 Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Derivatives in hedging relationships Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) and recognized in other interest expense $ — $ 141 $ — $ 312 Derivatives not designated as hedging instruments Amount of gain (loss) recognized in mortgage banking, net $ 12,395 $ 7,944 $ 45,881 $ 12,797 Amount of gain (loss) recognized in bank card and other fees (76 ) (487 ) (1,736 ) (743 ) The following table discloses the amount included in other comprehensive income (loss), net of tax, for derivative instruments designated as cash flow hedges for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Derivatives in cash flow hedging relationship Amount of gain (loss) recognized in other comprehensive income (loss), net of tax $ — $ (76 ) $ — $ (123 ) Trustmark’s interest rate swap derivative instruments are subject to master netting agreements, and therefore, eligible for offsetting in the consolidated balance sheets. Trustmark has elected to not offset any derivative instruments in its consolidated balance sheets. Information about financial instruments that are eligible for offset in the consolidated balance sheets as of June 30, 2020 and December 31, 2019 is presented in the following tables ($ in thousands): Offsetting of Derivative Assets As of June 30, 2020 Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets presented in the Statement of Financial Position Financial Instruments Cash Collateral Received Net Amount Derivatives $ 43,579 $ — $ 43,579 $ (1 ) $ — $ 43,578 Offsetting of Derivative Liabilities As of June 30, 2020 Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Position Net Amounts of Liabilities presented in the Statement of Financial Position Financial Instruments Cash Collateral Posted Net Amount Derivatives $ 1,932 $ — $ 1,932 $ (1 ) $ (1,931 ) $ — Offsetting of Derivative Assets As of December 31, 2019 Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets presented in the Statement of Financial Position Financial Instruments Cash Collateral Received Net Amount Derivatives $ 16,209 $ — $ 16,209 $ — $ — $ 16,209 Offsetting of Derivative Liabilities As of December 31, 2019 Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Position Net Amounts of Liabilities presented in the Statement of Financial Position Financial Instruments Cash Collateral Posted Net Amount Derivatives $ 1,122 $ — $ 1,122 $ — $ (1,390 ) $ (268 )

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Segment Information	Note 19 – Segment Information Trustmark’s management reporting structure includes three segments: General Banking, Wealth Management and Insurance. For a complete overview of Trustmark’s operating segments, see Note 22 – Segment Information included in Part II. Item 8. – Financial Statements and Supplementary Data, of Trustmark’s 2019 Annual Report. During the first quarter of 2020, Trustmark revised the composition of its operating segments by moving the Retail Private Banking Group from the General Banking Segment to the Wealth Management Segment as a result of a change in supervision of this group for segment reporting purposes. The prior period amounts presented include reclassifications to conform to the current period presentation. The accounting policies of each reportable segment are the same as those of Trustmark except for its internal allocations. Noninterest expenses for back-office operations support are allocated to segments based on estimated uses of those services. Trustmark measures the net interest income of its business segments with a process that assigns cost of funds or earnings credit on a matched-term basis. This process, called “funds transfer pricing”, charges an appropriate cost of funds to assets held by a business unit, or credits the business unit for potential earnings for carrying liabilities. The net of these charges and credits flows through to the General Banking Segment, which contains the management team responsible for determining TNB’s funding and interest rate risk strategies. The following table discloses financial information by reportable segment for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 General Banking Net interest income $ 103,376 $ 105,897 $ 205,779 $ 208,902 Provision for credit losses 18,188 2,596 36,562 4,289 Noninterest income 50,051 30,808 95,227 53,721 Noninterest expense 103,355 90,093 209,805 180,108 Income before income taxes 31,884 44,016 54,639 78,226 Income taxes 4,093 5,362 6,184 9,517 General banking net income $ 27,791 $ 38,654 $ 48,455 $ 68,709 Selected Financial Information Total assets $ 15,378,653 $ 13,161,680 $ 15,378,653 $ 13,161,680 Depreciation and amortization $ 10,422 $ 9,592 $ 19,216 $ 18,731 Wealth Management Net interest income $ 1,576 $ 1,772 $ 3,080 $ 3,520 Provision for credit losses (3 ) (4 ) 2,204 (8 ) Noninterest income 7,550 7,740 16,066 15,443 Noninterest expense 6,944 7,727 15,460 15,390 Income before income taxes 2,185 1,789 1,482 3,581 Income taxes 547 447 371 891 Wealth management net income $ 1,638 $ 1,342 $ 1,111 $ 2,690 Selected Financial Information Total assets $ 232,467 $ 313,398 $ 232,467 $ 313,398 Depreciation and amortization $ 67 $ 68 $ 134 $ 137 Insurance Net interest income $ 48 $ 55 $ 93 $ 110 Noninterest income 11,910 11,091 23,482 21,966 Noninterest expense 8,360 8,281 17,204 16,624 Income before income taxes 3,598 2,865 6,371 5,452 Income taxes 877 721 1,569 1,372 Insurance net income $ 2,721 $ 2,144 $ 4,802 $ 4,080 Selected Financial Information Total assets $ 80,959 $ 73,880 $ 80,959 $ 73,880 Depreciation and amortization $ 171 $ 126 $ 306 $ 255 Consolidated Net interest income $ 105,000 $ 107,724 $ 208,952 $ 212,532 Provision for credit losses 18,185 2,592 38,766 4,281 Noninterest income 69,511 49,639 134,775 91,130 Noninterest expense 118,659 106,101 242,469 212,122 Income before income taxes 37,667 48,670 62,492 87,259 Income taxes 5,517 6,530 8,124 11,780 Consolidated net income $ 32,150 $ 42,140 $ 54,368 $ 75,479 Selected Financial Information Total assets $ 15,692,079 $ 13,548,958 $ 15,692,079 $ 13,548,958 Depreciation and amortization $ 10,660 $ 9,786 $ 19,656 $ 19,123

Accounting Policies Recently Ad

Accounting Policies Recently Adopted and Pending Accounting Pronouncements	6 Months Ended
	Jun. 30, 2020
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Accounting Policies Recently Adopted and Pending Accounting Pronouncements	Note 20 – Accounting Policies Recently Adopted and Pending Accounting Pronouncements Accounting Policies Recently Adopted Except for the changes detailed below, Trustmark has consistently applied its accounting policies to all periods presented in the accompanying consolidated financial statements. ASU 2018-15, “Intangibles-Goodwill and Other–Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force).” Issued in August 2018, ASU 2018-15 aims to reduce complexity in the accounting for costs of implementing a cloud computing service arrangement. ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The amendments of ASU 2018-15 require an entity to follow the guidance in FASB ASC Subtopic 350-40, “Intangibles-Goodwill and Other-Internal-Use Software,” in order to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. The amendments of ASU 2018-15 also require an entity to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting arrangement (i.e. the noncancellable period of the arrangement plus periods covered by (1) an option to extend the arrangement if the entity is reasonably certain to exercise that option, (2) an option to terminate the arrangement if the entity is reasonably certain not to exercise the option, and (3) an option to extend (or not to terminate) the arrangement in which exercise of the option is in the control of the vendor). ASU 2018-15 also requires an entity to present the expense related to the capitalized implementation costs in the same line item in the statement of income as the fees associated with the hosting element (service) of the arrangement, and to classify payments for capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. ASU 2018-15 became effective for Trustmark on January 1, 2020. Trustmark does not currently have any material amount of implementation costs related to hosting arrangements that are service contracts within the scope of this ASU; therefore, adoption of ASU 2018-15 did not impact Trustmark’s consolidated financial statements. ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” Issued in August 2018, the amendments in this ASU remove disclosure requirements in FASB ASC Topic 820 related to (1) the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy; (2) the policy for timing of transfers between levels; (3) the valuation processes for Level 3 fair value measurements; and (4) for non-public entities, the changes in unrealized gains and losses for the period included in earnings for recurring Level 3 fair value measurements held at the end of the reporting period. The ASU also modifies disclosure requirements such that (1) in place of a rollforward for Level 3 fair value measurements, a non-public entity is required to disclose transfers into and out of Level 3 of the fair value hierarchy and purchases and issues of Level 3 assets and liabilities; (2) for investments in certain entities that calculate net asset value, an entity is required to disclose the timing of liquidation of an investee’s assets and the date that restrictions from redemption might lapse, only if the investee has communicated the timing to the entity or announced the timing publicly; and (3) it is clear that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date. Additionally, this ASU adds disclosure requirements for public entities about (1) the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period, and (2) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The amendments of ASU 2018-13 became effective for Trustmark on January 1, 2020. Adoption of ASU 2018-13 did not have a material impact on Trustmark’s consolidated financial statements. Disclosures required by FASB ASC Topic 820 are presented in Note 17 – Fair Value, of this report. ASU 2017-04, “ Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” Issued in January 2017, ASU 2017-04 simplifies the manner in which an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit's goodwill with the carrying amount of that goodwill. In computing the implied fair value of goodwill under Step 2, an entity, prior to the amendments in ASU 2017-04, had to perform procedures to determine the fair value at the impairment testing date of its assets and liabilities, including unrecognized assets and liabilities, in accordance with the procedure that would be required in determining the fair value of assets acquired and liabilities assumed in a business combination. However, under the amendments in ASU 2017-04, an entity should (1) perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and (2) recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value, with the understanding that the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, ASU 2017-04 removes the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails such qualitative test, to perform Step 2 of the goodwill impairment test. ASU 2017-04 became effective for Trustmark on January 1, 2020, and the amendments of this ASU will be applicable to the annual goodwill impairment test performed as of October 1, 2020. Based on Trustmark’s annual goodwill impairment test performed as of October 1, 2019, the fair value of its reporting units exceeded the carrying value and, therefore, the related goodwill was not impaired. ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” Issued in June 2016, ASU 2016-13 will add FASB ASC Topic 326, “Financial Instruments-Credit Losses” and finalizes amendments to FASB ASC Subtopic 825-15, “Financial Instruments-Credit Losses.” The amendments of ASU 2016-13 are intended to provide financial statement users with more decision-useful information related to expected credit losses on financial instruments and other commitments to extend credit by replacing the current incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. The amendments of ASU 2016-13 eliminate the probable initial recognition threshold and, in turn, reflect an entity’s current estimate of all expected credit losses. ASU 2016-13 does not specify the method for measuring expected credit losses, and an entity is allowed to apply methods that reasonably reflect its expectations of the credit loss estimate. Additionally, the amendments of ASU 2016-13 require that credit losses on available for sale debt securities be presented as an allowance rather than as a write-down. The amendments of ASU 2016-13, and all subsequent ASUs issued by FASB to provide additional guidance and clarification related to this Topic, became effective for Trustmark on January 1, 2020. As previously disclosed, Trustmark established a cross-functional Current Expected Credit Loss (CECL) Steering Committee, a CECL Solution Development Working Group and a CECL Working Group which included the appropriate members of Management to evaluate the impact this ASU, and all subsequent ASUs issued by FASB, will have on Trustmark’s financial position, results of operations and financial statement disclosures and determine the most appropriate method of implementing the amendments in these ASUs as well as any resources needed to implement the amendments. Trustmark selected a third-party vendor to provide allowance for loan loss software as well as advisory services in developing a new methodology that would be compliant with amendments of ASU 2016-13. In accordance with the amendments of ASU 2016-13, Trustmark elected to maintain pools of loans that were previously accounted for under FASB ASC Subtopic 310-30 and will continue to account for these pools as a unit of account. Loans are only removed from the existing loan pools if they are written off, paid off or sold. Upon adoption of ASU 2016-13, the allowance for credit losses was determined for each pool and added to the pool’s carrying value to establish a new amortized cost basis. The difference between the unpaid principle balance of the pool and the new amortized cost basis is the noncredit premium or discount which will be amortized into interest income over the remaining life of the pool. As a result of adopting the amendments of ASU 2016-13, Trustmark recorded a decrease to its ACL LHFI of $3.0 million and an increase to its ACL on off-balance sheet credit exposures of $29.6 million resulting in a one-time cumulative effect adjustment through retained earnings of $26.6 million ($19.9 million, net of tax) at the date of adoption. This adjustment included a qualitative adjustment to the allowance for credit losses related to loans and an allowance on off-balance sheet credit exposures. Trustmark estimates losses over an approximate one-year forecast period using Moody’s baseline economic forecasts, and then reverts to longer term historical loss experience over a one-year period. Trustmark’s estimated allowance for credit losses on both held to maturity securities and available for sale securities under the CECL model was deemed immaterial due to the composition of the portfolios being primarily government agency-backed securities for which the risk of loss is minimal. Therefore, Trustmark did not recognize a cumulative effective adjustment through retained earnings at the date of adoption related to the held to maturity or available for sale securities. Disclosures required by the amendments ASU 2016-13 are presented in Note 2 – Securities Available for Sale and Held to Maturity and Note 3 – Loans Held for Investment and Allowance for Credit Losses, of this report. Pending Accounting Pronouncements ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” Issued in March 2020, ASU 2020-04 seeks to provided additional guidance, for a limited time, to ease the potential burden in accounting for or recognizing the effects of reference rate reform on financial reporting. The FASB issued ASU 2020-04 is response to concerns about the structural risks of interbank offered rates (IBORs) and, in particular, the risk that the London Interbank Offer Rate (LIBOR) will no longer be used. Regulators have begun reference rate reform initiatives to identify alternative reference rates that are more observable or transaction-based and less susceptible to manipulation. Stakeholders have raised operational challenges likely to arise with the reference rate reform, particularly related to contract modifications and hedge accounting. The amendments of ASU 2020-04, which are elective and apply to all entities, provide expedients and exceptions for applying GAAP to contract modifications and hedging relationships affected by the reference rate reform id certain criteria are met. The amendments apply only to contracts and hedging relationships that reference LIBOR or another reference rate that is expected to be discontinued due to reference rate reform. The optional expedients for contract modifications should be applied consistently for all contracts or transactions within the relevant Codification Topic or Subtopic or Industry Subtopic that contains the related guidance. The optional expedients for hedging relationships can be elected on an individual hedging relationship basis. As the guidance in ASU 2020-04 is intended to assist entity’s during the global market-wide reference rate transition period, it is in effect for a limited time, from March 12, 2020 through December 31, 2022. Management is currently evaluating the impact to Trustmark as a result of the potential discontinuance of LIBOR, and a determination cannot be made at this time as to the impact the amendments of ASU 2020-04 or the reference rate reform will have on its consolidated financial statements. ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” Issued in December 2019, ASU 2019-12 seeks to simplify the accounting for income taxes by removing certain exceptions to the general principles in FASB ASC Topic 740, Income Taxes. In particular, the amendments of ASU 2019-12 remove the exceptions to (1) the incremental approach for intra-period tax allocation when there is a loss from continuing operations and income or a gain from other items (e.g., discontinued operations or other comprehensive income); (2) the requirement to recognize a deferred tax liability for equity method investments when a foreign subsidiary becomes an equity method investment; (3) the ability not to recognize a deferred tax liability for a foreign subsidiary when a foreign equity method investment becomes a subsidiary; and (4) the general methodology for calculating income taxes in an interim period when a year-to-date loss exceeds the anticipated loss for the year. The amendments of ASU 2019-12 (1) require that an entity recognize a franchise tax (or similar tax), that is partially based on income, in accordance with FASB ASC Topic 740 and account for any incremental amount incurred as a non-income-based tax; (2) require that an entity evaluate when a step up in the tax basis of goodwill should be considered part of the business combination in which the book goodwill was originally recognized and when it should instead be considered a separate transaction; (3) specify that an entity is not required to allocate the consolidated amount of current and deferred tax expense to a legal entity that is not subject to tax in its separate financial statements, but rather may elect to do so for a legal entity that is both not subject to tax and disregarded by the taxing authority; and (4) require that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. ASU 2019-12 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption of ASU 2019-12 is permitted, including adoption in any interim period for periods for which financial statements have not yet been issued. An entity that elects to early adopt the amendments in an interim period should reflect any adjustments as of the beginning of the annual period that includes that interim period. Additionally, an entity that elects early adoption must adopt all the amendments in the same period. The amendments related to separate financial statements of legal entities that are not subject to tax should be applied on a retrospective basis for all periods presented. The amendments related to changes in ownership of foreign equity method investments or foreign subsidiaries should be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. The amendments related to franchise taxes that are partially based on income should be applied on either a retrospective basis for all periods presented or a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. All other amendments should be applied on a prospective basis. Trustmark intends to adopt the amendments in ASU 2019-12 during the first quarter of 2021. Adoption of ASU 2019-12 is not expected to have a material impact to Trustmark’s consolidated financial statements. ASU 2018-14, “Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans.” Issued in August 2018, ASU 2018-14 modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The amendments in ASU 2018-14 remove certain disclosure requirements that are no longer considered cost beneficial, clarify the specific requirements of disclosures and add disclosure requirements identified as relevant. T he amendments of ASU 2018-14 become effective for fiscal years beginning after December 15, 2020. Trustmark plans to adopt these amendments during the first quarter of 2021. Management is currently assessing all the potential impacts of the amendments in ASU 2018-14 on Trustmark’s consolidated financial statements; however, the adoption of ASU 2018-14 is not expected to have a material impact on Trustmark’s consolidated financial statements.

Accounting Policies Recently _2

Accounting Policies Recently Adopted and Pending Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Credit Loss, Financial Instrument	In order to comply with ASU 2016-13, Trustmark conducted a review of its investment portfolio and determined that for certain classes of securities it would be appropriate to assume the expected credit loss to be zero. This zero-credit loss assumption applies to debt issuances of the U.S. Treasury and agencies and instrumentalities of the United States government. The reasons behind the adoption of the zero-credit loss assumption were as follows: • High credit rating • Long history with no credit losses • Guaranteed by a sovereign entity • Widely recognized as “risk-free rate” • Can print its own currency • Currency is routinely held by central banks, used in international commerce, and commonly viewed as reserve currency • Currently under the U.S. Government conservatorship or receivership Trustmark will continuously monitor any changes in economic conditions, credit downgrades, changes to explicit or implicit guarantees granted to certain debt issuers, and any other relevant information that would indicate potential credit deterioration and prompt Trustmark to reconsider its zero-credit loss assumption.
Securities Available for Sale	Securities Available for Sale ASU 2016-13 makes targeted improvements to the accounting for credit losses on securities available for sale. The concept of other-than-temporarily impaired has been replaced with the allowance for credit losses. Unlike securities held to maturity, securities available for sale are evaluated on an individual level and pooling of securities is not allowed. Quarterly, Trustmark evaluates if any securit y ha s a fair value less than its amortized cost. Once these securities are identified, in order to determine whether a d ecline in fair value result ed from a credit loss or other factors , Trustmark perform s further analysis as outlined below: • Review the extent to which the fair value is less than the amortized cost and observe the security’s lowest credit rating as reported by third-party credit ratings companies. • The securities that violate the credit loss triggers above would be subjected to additional analysis that may include, but is not limited to: changes in market interest rates, changes in securities credit ratings, security type, service area economic factors, financial performance of the issuer/or obligor of the underlying issue and third-party guarantee. • If Trustmark determines that a credit loss exists, the credit portion of the allowance will be measured using a discounted cash flow (DCF) analysis using the effective interest rate as of the security’s purchase date. The amount of credit loss Trustmark records will be limited to the amount by which the amortized cost exceeds the fair value. The DCF analysis utilizes contractual maturities, as well as third-party credit ratings and cumulative default rates published annually by Moody’s Investor Service (Moody’s). At June 30, 2020, the results of the analysis did not identify any securities that violate the credit loss triggers; therefore, no DCF analysis was performed and no credit loss was recognized on any of the securities available for sale. Accrued interest receivable is excluded from the estimate of credit losses for securities available for sale. At June 30, 2020, accrued interest receivable totaled $4.2 million for securities available for sale and was reported in other assets on the accompanying consolidated balance sheet.
Securities Held to Maturity	Securities Held to Maturity ASU 2016-13 requires institutions to measure expected credit losses on financial assets carried at amortized cost on a collective or pool basis when similar risks exist. Trustmark uses several levels of segmentation in order to measure expected credit losses: • The portfolio is segmented into agency and non-agency securities. • The non-agency securities are separated into municipal, mortgage, and corporate securities. Each individual segment is categorized by third-party credit ratings. As discussed above, Trustmark has determined that for certain classes of securities it would be appropriate to assume the expected credit loss to be zero, which include debt issuances of the U.S. Treasury and agencies and instrumentalities of the United States government. This assumption will be reviewed and attested to quarterly. Trustmark is using an internally built model to verify the accuracy of third-party provided calculations. At June 30, 2020, Trustmark’s securities held to maturity totaled $660.0 million. The potential credit loss exposure was $31.5 million and consisted of municipal securities. After applying appropriate probability of default and loss given default assumptions, the total amount of current expected credit losses was deemed immaterial. Therefore, no reserve was recorded at June 30, 2020. Accrued interest receivable is excluded from the estimate of credit losses for securities held to maturity. At June 30, 2020, accrued interest receivable totaled $1.4 million for securities held to maturity and was reported in other assets on the accompanying consolidated balance sheet. At June 30, 2020, Trustmark had no securities held to maturity that were past due 30 days or more as to principal or interest payments. Trustmark had no securities held to maturity classified as nonaccrual at June 30, 2020.
Allowance for Credit Losses, LHFI (ACL)	Allowance for Credit Losses, LHFI (ACL) Trustmark’s ACL methodology for LHFI is based upon guidance within FASB ASC Subtopic 326-20 as well as regulatory guidance from its primary regulator. The ACL is a valuation account that is deducted from the loans’ amortized cost basis to present the net amount expected to be collected on the loans. Credit quality within the LHFI portfolio is continuously monitored by Management and is reflected within the ACL for loans. The ACL is an estimate of expected losses inherent within Trustmark’s existing LHFI portfolio. The ACL for LHFI is adjusted through the provision for credit losses (PCL) and reduced by the charge off of loan amounts, net of recoveries. The loan loss estimation process involves procedures to appropriately consider the unique characteristics of Trustmark’s LHFI portfolio segments. These segments are further disaggregated into loan classes, the level at which credit risk is monitored. When computing allowance levels, credit loss assumptions are estimated using a model that categorizes loan pools based on loss history, delinquency status and other credit trends and risk characteristics, including current conditions and reasonable and supportable forecasts about the future. Evaluations of the portfolio and individual credits are inherently subjective, as they require estimates, assumptions and judgments as to the facts and circumstances of particular situations. Determining the appropriateness of the allowance is complex and requires judgement by Management about the effect of matters that are inherently uncertain. In future periods, evaluations of the overall LHFI portfolio, in light of the factors and forecasts then prevailing, may result in significant changes in the allowance and credit loss expense. Trustmark estimates the ACL using relevant available information, from internal and external sources, relating to past events, current conditions and reasonable and supportable forecasts including the COVID-19 pandemic effects. Trustmark uses a third-party software application to calculate the quantitative portion of the ACL using a methodology and assumptions specific to each loan pool. The qualitative portion of the allowance is based on general economic conditions and other internal and external factors affecting Trustmark as a whole as well as specific LHFI. Factors considered include the following: lending policies and procedures, economic conditions and concentrations of credit, nature and volume of the portfolio, performance trends, and external factors . The quantitative and qualitative portions of the allowance are added together to determine the total allowance for credit losses, which reflects Management’s expectations of future conditions based on reasonable and supportable forecasts. The methodology for estimating the amount of expected credit losses reported in the ACL has two basic components: a collective, or pooled, component for estimated expected credit losses for pools of loans that share similar risk characteristics, and an asset-specific component involving individual loans that do not share risk characteristics with other loans and the measurement of expected credit losses for such individual loans. In estimating the allowance for credit losses for the collective component, loans are segregated into loan pools based on loan product types and similar risk characteristics. The loans secured by real estate and other loans secured by real estate portfolio segments include loans for both commercial and residential properties. The underwriting process for these loans includes analysis of the financial position and strength of both the borrower and guarantor, experience with similar projects in the past, market demand and prospects for successful completion of the proposed project within the established budget and schedule, values of underlying collateral, availability of permanent financing, maximum loan-to-value ratios, minimum equity requirements, acceptable amortization periods and minimum debt service coverage requirements, based on property type. The borrower’s financial strength and capacity to repay their obligations remain the primary focus of underwriting. Financial strength is evaluated based upon analytical tools that consider historical and projected cash flows and performance in addition to analysis of the proposed project for income-producing properties. Additional support offered by guarantors is also considered. Ultimate repayment of these loans is sensitive to interest rate changes, general economic conditions, liquidity and availability of long-term financing. The commercial and industrial LHFI portfolio segment includes commercial loans made to many types of businesses for various purposes, such as short-term working capital loans that are usually secured by accounts receivable and inventory, equipment and fixed asset purchases that are secured by those assets and term financing for those within Trustmark’s geographic markets. Trustmark’s credit underwriting process for commercial and industrial loans includes analysis of historical and projected cash flows and performance, evaluation of financial strength of both borrowers and guarantors as reflected in current and detailed financial information and evaluation of underlying collateral to support the credit. The consumer LHFI portfolio segment is comprised of loans which are underwritten after evaluating a borrower’s capacity, credit and collateral. Several factors are considered when assessing a borrower’s capacity, including the borrower’s employment, income, current debt, assets and level of equity in the property. Credit is assessed using a credit report that provides credit scores and the borrower’s current and past information about their credit history. Property appraisals are obtained to assist in evaluating collateral. Loan-to-value and debt-to-income ratios, loan amount and lien position are also considered in assessing whether to originate a loan. These borrowers are particularly susceptible to downturns in economic trends such as conditions that negatively affect housing prices and demand and levels of unemployment. The state and other political subdivision LHFI and the other commercial LHFI portfolio segments primarily consist of loans to non-depository financial institutions, such as mortgage companies, finance companies and other financial intermediaries, loans to state and political subdivisions, and loans to non-profit and charitable organizations. These loans are underwritten based on the specific nature or purpose of the loan and underlying collateral with special consideration given to the specific source of repayment for the loan. The following table provides a description of each of Trustmark’s portfolio segments, loan classes, loan pools and the ACL methodology and loss drivers: Portfolio Segment Loan Class Loan Pool Methodology Loss Drivers Loans secured by real estate Construction, land development and other land 1-4 family residential construction DCF Prime Rate, National GDP Lots and development DCF Prime Rate, Southern Unemployment Unimproved land DCF Prime Rate, Southern Unemployment All other consumer DCF Prime Rate, Southern Unemployment Other secured by 1-4 family residential properties Consumer 1-4 family - 1st liens DCF Prime Rate, Southern Unemployment All other consumer DCF Prime Rate, Southern Unemployment Nonresidential owner-occupied DCF Southern Unemployment, National GDP Secured by nonfarm, nonresidential properties Nonowner-occupied - hotel/motel DCF Southern Vacancy Rate, Southern Unemployment Nonowner-occupied - office DCF Southern Vacancy Rate, Southern Unemployment Nonowner-occupied- Retail DCF Southern Vacancy Rate, Southern Unemployment Nonowner-occupied - senior living/nursing homes DCF Southern Vacancy Rate, Southern Unemployment Nonowner-occupied - all other DCF Southern Vacancy Rate, Southern Unemployment Nonresidential owner-occupied DCF Southern Unemployment, National GDP Other real estate secured Nonresidential nonowner -occupied - apartments DCF Southern Vacancy Rate, Southern Unemployment Nonresidential owner-occupied DCF Southern Unemployment, National GDP Nonowner-occupied - all other DCF Southern Vacancy Rate, Southern Unemployment Other loans secured by real estate Other construction Other construction WARM Prime Rate, National Unemployment Secured by 1-4 family residential properties Trustmark mortgage WARM Southern Unemployment Commercial and industrial loans Commercial and industrial loans Commercial and industrial - non-working capital DCF Trustmark historical data Commercial and industrial - working capital DCF Trustmark historical data Credit cards WARM Trustmark call report data Consumer loans Consumer loans Credit cards WARM Trustmark call report data Overdrafts Loss Rate Trustmark historical data All other consumer DCF Prime Rate, Southern Unemployment State and other political subdivision loans State and other political subdivision loans Obligations of state and political subdivisions DCF Moody's Bond Default Study Other commercial loans Other commercial loans Other loans DCF Prime Rate, Southern Unemployment Commercial and industrial - non-working capital DCF Trustmark historical data Commercial and industrial - working capital DCF Trustmark historical data In general, Trustmark utilizes a DCF method to estimate the quantitative portion of the allowance for credit losses for loan pools. The DCF model consists of two key components, a loss driver analysis (LDA) and a cash flow analysis. For loan pools utilizing the DCF methodology, multiple assumptions are in place, depending on the loan pool. A reasonable and supportable forecast is utilized for each loan pool by developing a LDA for each loan class. The LDA uses charge off data from Federal Financial Institutions Examination Council ( FFIEC ) reports to construct a periodic default rate (PDR). The PDR is decomposed into a probability of default (PD). Regressions are run using the data for various macroeconomic variables in order to determine which ones correlate to Trustmark’s losses. These variables are then incorporated into the application to calculate a quarterly PD using a third-party baseline forecast. In addition to the PD, a loss given default (LGD) is derived using a method referred to as Frye Jacobs. The Frye Jacobs method is a mathematical formula that traces the relationship between LGD and PD over time and projects the LGD based on the levels of PD forecasts. This model approach is applicable to all pools within the construction , land development and other land, other secured by 1-4 family residential properties, secured by nonfarm, nonresidential properties and other real estate secure d loan classes as well as the all other consumer and other loans pools. For the commercial and industrial loans related pools, Trustmark uses its own PD and LGD data, instead of the macroeconomic variables and the Frye Jacobs method described above, to calculate the PD and LGD as there were no defensible macroeconomic variables that correlated to Trustmark’s losses. Trustmark utilizes a third-party Bond Default Study to derive the PD and LGD for the obligations of state and political subdivisions pool. Due to the lack of losses within this pool, no defensible macroeconomic factors were identified to correlate. The PD and LGD measures are used in conjunction with prepayment data as inputs into the DCF model to calculate the cash flows at the individual loan level. Contractual cash flows based on loan terms are adjusted for PD, LGD and prepayments to derive loss cash flows. These loss cash flows are discounted by the loan’s coupon rate to arrive at the discounted cash flow based quantitative loss. The prepayment studies are updated quarterly by a third-party for each applicable pool. An alternate method of estimating the ACL is used for certain loan pools due to specific characteristics of these loans. For the non-DCF pools, specifically, those using the weighted average remaining maturity (WARM) method, the remaining life is incorporated into the ACL quantitative calculation. Trustmark determined that reasonable and supportable forecasts could be made for a twelve-month period for all of its loan pools. To the extent the lives of the loans in the LHFI portfolio extend beyond this forecast period, Trustmark uses a reversion period of four quarters and reverts to the historical mean on a straight-line basis over the remaining life of the loans. The econometric models in production today reflect segment or pool level sensitivities of probability of default (PD) to changes in macroeconomic variables. By measuring the relationship between defaults and changes in the economy, the quantitative reserve incorporates reasonable and supportable forecasts of future conditions that will affect the value of its assets, as required by FASB ASC Topic 326. Under stable forecasts, these linear regressions will reasonably predict a pool’s PD. However, due to the COVID-19 pandemic, the macroeconomic variables used for reasonable and supportable forecasting have changed rapidly. At the current levels, it is not clear that the models currently in production will produce reasonably representative results since the models were originally estimated using data beginning in 2004 through 2017. During this period, a traditional albeit severe economic recession occurred. Thus, econometric models are sensitive to similar future levels of PD. During the second quarter of 2020, Trustmark revised its ACL methodology in order to prevent the econometric models from extrapolating beyond reasonable boundaries of their input variables. Trustmark chose to establish an upper and lower limit process when applying the periodic forecasts. In this way, Management will not rely upon unobserved and untested relationships in the setting of the quantitative reserve. This approach applies to all input variables, including: South Census Unemployment, National Unemployment, National GDP, South Census Vacancy Rate and the Prime Rate. The upper and lower limits are based on the distribution of the macroeconomic variable by selecting extreme percentiles at the upper and lower limits of the distribution, the 1st and 99th, respectively. These upper and lower limits are then used to calculate the PD for the forecast time period in which the forecasted values are outside of the upper and lower limit range. For the current period, the forecast related to the macroeconomic variables used in the quantitative modeling process were adversely affected due to the impact of COVID-19, causing an overall increase in reserve levels. Qualitative factors used in the ACL methodology include the following: • Lending policies and procedures • Economic conditions and concentrations of credit • Nature and volume of the portfolio • Performance trends • External factors While all these factors are incorporated into the overall methodology, only two are currently considered active: economic conditions and concentrations of credit and performance trends. Two of Trustmark’s largest loan classes are the loans secured by nonfarm, nonresidential properties and the loans secured by other real estate . Trustmark elected to create a qualitative factor specifically for the se loan classes which address es changes in the economic conditions of metropolitan areas and appl ies additional pool level reserves. This qualitative factor is based on third - party market data and forecast trends and is updated quarterly as information is available, by market and by loan pool . For the performance trends factor, Trustmark uses migration analyses to allocate additional ACL to non-pass/delinquent loans within each pool. In this way, Management believes the ACL will directly reflect changes in risk, based on the performance of the loans within a pool, whether declining or improving. The ACL for individual loans that do not share risk characteristics with other loans is measured as the difference between the discounted value of expected future cash flows, based in the effective interest rate at origination, and the amortized cost basis of the loan, or the net realizable value. The ACL is the difference between the loan’s net realizable value and its amortized cost basis (net of previous charge-offs and deferred loan fees and costs), except for collateral-dependent loans. A loan is collateral dependent when the borrower is experiencing financial difficulty and repayment of the loan is expected to be provided substantially through the sale of the collateral. The expected credit loss for collateral-dependent loans is measured as the difference between the amortized cost basis of the loan and the fair value of the collateral, adjusted for the estimated cost to sell. Fair value estimates for collateral-dependent loans are derived from appraised values based on the current market value or the ‘as is’ value of the collateral, normally from recently received and reviewed appraisals. Current appraisals are ordered on an annual basis based on the inspection date or more often if market conditions necessitate. Appraisals are obtained from state-certified appraisers and are based on certain assumptions, which may include construction or development status and the highest and best use of the property. These appraisals are reviewed by Trustmark’s Appraisal Review Department to ensure they are acceptable, and values are adjusted down for costs associated with asset disposal. If the calculated expected credit loss is determined to be permanent or not recoverable, the amount of the expected credit loss is charged off. LHFI are charged off against the ACL, with any subsequent recoveries credited back to the ACL account. Expected recoveries may not exceed the aggregate of amounts previously charged off and expected to be charged off. Trustmark’s loan policy dictates the guidelines to be followed in determining when a loan is charged off. Commercial purpose LHFI are charged off when a determination is made that the loan is uncollectible and continuance as a bankable asset is not warranted. Consumer LHFI secured by 1-4 family residential real estate are generally charged off or written down to the fair value of the collateral less cost to sell at no later than 180 days of delinquency. Non-real estate consumer purpose LHFI, including both secured and unsecured loans, are generally charged off by 120 days of delinquency. Consumer revolving lines of credit and credit card debt are generally charged off on or prior to 180 days of delinquency.
Accounting Policies Recently Adopted and Pending Accounting Pronouncements	Accounting Policies Recently Adopted Except for the changes detailed below, Trustmark has consistently applied its accounting policies to all periods presented in the accompanying consolidated financial statements. ASU 2018-15, “Intangibles-Goodwill and Other–Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force).” Issued in August 2018, ASU 2018-15 aims to reduce complexity in the accounting for costs of implementing a cloud computing service arrangement. ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The amendments of ASU 2018-15 require an entity to follow the guidance in FASB ASC Subtopic 350-40, “Intangibles-Goodwill and Other-Internal-Use Software,” in order to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. The amendments of ASU 2018-15 also require an entity to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting arrangement (i.e. the noncancellable period of the arrangement plus periods covered by (1) an option to extend the arrangement if the entity is reasonably certain to exercise that option, (2) an option to terminate the arrangement if the entity is reasonably certain not to exercise the option, and (3) an option to extend (or not to terminate) the arrangement in which exercise of the option is in the control of the vendor). ASU 2018-15 also requires an entity to present the expense related to the capitalized implementation costs in the same line item in the statement of income as the fees associated with the hosting element (service) of the arrangement, and to classify payments for capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. ASU 2018-15 became effective for Trustmark on January 1, 2020. Trustmark does not currently have any material amount of implementation costs related to hosting arrangements that are service contracts within the scope of this ASU; therefore, adoption of ASU 2018-15 did not impact Trustmark’s consolidated financial statements. ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” Issued in August 2018, the amendments in this ASU remove disclosure requirements in FASB ASC Topic 820 related to (1) the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy; (2) the policy for timing of transfers between levels; (3) the valuation processes for Level 3 fair value measurements; and (4) for non-public entities, the changes in unrealized gains and losses for the period included in earnings for recurring Level 3 fair value measurements held at the end of the reporting period. The ASU also modifies disclosure requirements such that (1) in place of a rollforward for Level 3 fair value measurements, a non-public entity is required to disclose transfers into and out of Level 3 of the fair value hierarchy and purchases and issues of Level 3 assets and liabilities; (2) for investments in certain entities that calculate net asset value, an entity is required to disclose the timing of liquidation of an investee’s assets and the date that restrictions from redemption might lapse, only if the investee has communicated the timing to the entity or announced the timing publicly; and (3) it is clear that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date. Additionally, this ASU adds disclosure requirements for public entities about (1) the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period, and (2) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The amendments of ASU 2018-13 became effective for Trustmark on January 1, 2020. Adoption of ASU 2018-13 did not have a material impact on Trustmark’s consolidated financial statements. Disclosures required by FASB ASC Topic 820 are presented in Note 17 – Fair Value, of this report. ASU 2017-04, “ Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” Issued in January 2017, ASU 2017-04 simplifies the manner in which an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit's goodwill with the carrying amount of that goodwill. In computing the implied fair value of goodwill under Step 2, an entity, prior to the amendments in ASU 2017-04, had to perform procedures to determine the fair value at the impairment testing date of its assets and liabilities, including unrecognized assets and liabilities, in accordance with the procedure that would be required in determining the fair value of assets acquired and liabilities assumed in a business combination. However, under the amendments in ASU 2017-04, an entity should (1) perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and (2) recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value, with the understanding that the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, ASU 2017-04 removes the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails such qualitative test, to perform Step 2 of the goodwill impairment test. ASU 2017-04 became effective for Trustmark on January 1, 2020, and the amendments of this ASU will be applicable to the annual goodwill impairment test performed as of October 1, 2020. Based on Trustmark’s annual goodwill impairment test performed as of October 1, 2019, the fair value of its reporting units exceeded the carrying value and, therefore, the related goodwill was not impaired. ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” Issued in June 2016, ASU 2016-13 will add FASB ASC Topic 326, “Financial Instruments-Credit Losses” and finalizes amendments to FASB ASC Subtopic 825-15, “Financial Instruments-Credit Losses.” The amendments of ASU 2016-13 are intended to provide financial statement users with more decision-useful information related to expected credit losses on financial instruments and other commitments to extend credit by replacing the current incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. The amendments of ASU 2016-13 eliminate the probable initial recognition threshold and, in turn, reflect an entity’s current estimate of all expected credit losses. ASU 2016-13 does not specify the method for measuring expected credit losses, and an entity is allowed to apply methods that reasonably reflect its expectations of the credit loss estimate. Additionally, the amendments of ASU 2016-13 require that credit losses on available for sale debt securities be presented as an allowance rather than as a write-down. The amendments of ASU 2016-13, and all subsequent ASUs issued by FASB to provide additional guidance and clarification related to this Topic, became effective for Trustmark on January 1, 2020. As previously disclosed, Trustmark established a cross-functional Current Expected Credit Loss (CECL) Steering Committee, a CECL Solution Development Working Group and a CECL Working Group which included the appropriate members of Management to evaluate the impact this ASU, and all subsequent ASUs issued by FASB, will have on Trustmark’s financial position, results of operations and financial statement disclosures and determine the most appropriate method of implementing the amendments in these ASUs as well as any resources needed to implement the amendments. Trustmark selected a third-party vendor to provide allowance for loan loss software as well as advisory services in developing a new methodology that would be compliant with amendments of ASU 2016-13. In accordance with the amendments of ASU 2016-13, Trustmark elected to maintain pools of loans that were previously accounted for under FASB ASC Subtopic 310-30 and will continue to account for these pools as a unit of account. Loans are only removed from the existing loan pools if they are written off, paid off or sold. Upon adoption of ASU 2016-13, the allowance for credit losses was determined for each pool and added to the pool’s carrying value to establish a new amortized cost basis. The difference between the unpaid principle balance of the pool and the new amortized cost basis is the noncredit premium or discount which will be amortized into interest income over the remaining life of the pool. As a result of adopting the amendments of ASU 2016-13, Trustmark recorded a decrease to its ACL LHFI of $3.0 million and an increase to its ACL on off-balance sheet credit exposures of $29.6 million resulting in a one-time cumulative effect adjustment through retained earnings of $26.6 million ($19.9 million, net of tax) at the date of adoption. This adjustment included a qualitative adjustment to the allowance for credit losses related to loans and an allowance on off-balance sheet credit exposures. Trustmark estimates losses over an approximate one-year forecast period using Moody’s baseline economic forecasts, and then reverts to longer term historical loss experience over a one-year period. Trustmark’s estimated allowance for credit losses on both held to maturity securities and available for sale securities under the CECL model was deemed immaterial due to the composition of the portfolios being primarily government agency-backed securities for which the risk of loss is minimal. Therefore, Trustmark did not recognize a cumulative effective adjustment through retained earnings at the date of adoption related to the held to maturity or available for sale securities. Disclosures required by the amendments ASU 2016-13 are presented in Note 2 – Securities Available for Sale and Held to Maturity and Note 3 – Loans Held for Investment and Allowance for Credit Losses, of this report. Pending Accounting Pronouncements ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” Issued in March 2020, ASU 2020-04 seeks to provided additional guidance, for a limited time, to ease the potential burden in accounting for or recognizing the effects of reference rate reform on financial reporting. The FASB issued ASU 2020-04 is response to concerns about the structural risks of interbank offered rates (IBORs) and, in particular, the risk that the London Interbank Offer Rate (LIBOR) will no longer be used. Regulators have begun reference rate reform initiatives to identify alternative reference rates that are more observable or transaction-based and less susceptible to manipulation. Stakeholders have raised operational challenges likely to arise with the reference rate reform, particularly related to contract modifications and hedge accounting. The amendments of ASU 2020-04, which are elective and apply to all entities, provide expedients and exceptions for applying GAAP to contract modifications and hedging relationships affected by the reference rate reform id certain criteria are met. The amendments apply only to contracts and hedging relationships that reference LIBOR or another reference rate that is expected to be discontinued due to reference rate reform. The optional expedients for contract modifications should be applied consistently for all contracts or transactions within the relevant Codification Topic or Subtopic or Industry Subtopic that contains the related guidance. The optional expedients for hedging relationships can be elected on an individual hedging relationship basis. As the guidance in ASU 2020-04 is intended to assist entity’s during the global market-wide reference rate transition period, it is in effect for a limited time, from March 12, 2020 through December 31, 2022. Management is currently evaluating the impact to Trustmark as a result of the potential discontinuance of LIBOR, and a determination cannot be made at this time as to the impact the amendments of ASU 2020-04 or the reference rate reform will have on its consolidated financial statements. ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” Issued in December 2019, ASU 2019-12 seeks to simplify the accounting for income taxes by removing certain exceptions to the general principles in FASB ASC Topic 740, Income Taxes. In particular, the amendments of ASU 2019-12 remove the exceptions to (1) the incremental approach for intra-period tax allocation when there is a loss from continuing operations and income or a gain from other items (e.g., discontinued operations or other comprehensive income); (2) the requirement to recognize a deferred tax liability for equity method investments when a foreign subsidiary becomes an equity method investment; (3) the ability not to recognize a deferred tax liability for a foreign subsidiary when a foreign equity method investment becomes a subsidiary; and (4) the general methodology for calculating income taxes in an interim period when a year-to-date loss exceeds the anticipated loss for the year. The amendments of ASU 2019-12 (1) require that an entity recognize a franchise tax (or similar tax), that is partially based on income, in accordance with FASB ASC Topic 740 and account for any incremental amount incurred as a non-income-based tax; (2) require that an entity evaluate when a step up in the tax basis of goodwill should be considered part of the business combination in which the book goodwill was originally recognized and when it should instead be considered a separate transaction; (3) specify that an entity is not required to allocate the consolidated amount of current and deferred tax expense to a legal entity that is not subject to tax in its separate financial statements, but rather may elect to do so for a legal entity that is both not subject to tax and disregarded by the taxing authority; and (4) require that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. ASU 2019-12 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption of ASU 2019-12 is permitted, including adoption in any interim period for periods for which financial statements have not yet been issued. An entity that elects to early adopt the amendments in an interim period should reflect any adjustments as of the beginning of the annual period that includes that interim period. Additionally, an entity that elects early adoption must adopt all the amendments in the same period. The amendments related to separate financial statements of legal entities that are not subject to tax should be applied on a retrospective basis for all periods presented. The amendments related to changes in ownership of foreign equity method investments or foreign subsidiaries should be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. The amendments related to franchise taxes that are partially based on income should be applied on either a retrospective basis for all periods presented or a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. All other amendments should be applied on a prospective basis. Trustmark intends to adopt the amendments in ASU 2019-12 during the first quarter of 2021. Adoption of ASU 2019-12 is not expected to have a material impact to Trustmark’s consolidated financial statements. ASU 2018-14, “Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans.” Issued in August 2018, ASU 2018-14 modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The amendments in ASU 2018-14 remove certain disclosure requirements that are no longer considered cost beneficial, clarify the specific requirements of disclosures and add disclosure requirements identified as relevant. T he amendments of ASU 2018-14 become effective for fiscal years beginning after December 15, 2020. Trustmark plans to adopt these amendments during the first quarter of 2021. Management is currently assessing all the potential impacts of the amendments in ASU 2018-14 on Trustmark’s consolidated financial statements; however, the adoption of ASU 2018-14 is not expected to have a material impact on Trustmark’s consolidated financial statements.

Securities Available for Sale_2

Securities Available for Sale and Held to Maturity (Tables)	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
Securities Held to Maturity by Credit Rating, as Determined by Moody's	The following table presents the amortized cost of Trustmark’s securities held to maturity by credit rating, as determined by Moody’s, at June 30, 2020 ($ in thousands): Securities Held to Maturity June 30, 2020 Amortized Cost Aaa $ 628,419 Aa1 to Aa3 26,179 Not Rated (1) 5,450 Total $ 660,048 (1) Not rated securities primarily consist of Mississippi municipal general obligations.
Amortized Cost and Estimated Fair Value of Available for Sale and Held to Maturity Securities	The following tables are a summary of the amortized cost and estimated fair value of securities available for sale and held to maturity at June 30, 2020 and December 31, 2019 ($ in thousands): Securities Available for Sale Securities Held to Maturity June 30, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. Government agency obligations $ 20,254 $ 160 $ (516 ) $ 19,898 $ — $ — $ — $ — Obligations of states and political subdivisions 10,565 611 — 11,176 31,629 461 (25 ) 32,065 Mortgage-backed securities Residential mortgage pass-through securities Guaranteed by GNMA 67,439 2,199 (1 ) 69,637 10,306 548 — 10,854 Issued by FNMA and FHLMC 1,096,861 24,762 (19 ) 1,121,604 86,346 3,204 — 89,550 Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 560,109 14,846 (15 ) 574,940 435,333 23,148 — 458,481 Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 84,350 2,558 (10 ) 86,898 96,434 3,177 — 99,611 Total $ 1,839,578 $ 45,136 $ (561 ) $ 1,884,153 $ 660,048 $ 30,538 $ (25 ) $ 690,561 December 31, 2019 U.S. Government agency obligations $ 22,965 $ 69 $ (707 ) $ 22,327 $ 3,781 $ 220 $ — $ 4,001 Obligations of states and political subdivisions 24,952 513 — 25,465 31,781 434 (53 ) 32,162 Mortgage-backed securities Residential mortgage pass-through securities Guaranteed by GNMA 69,196 425 (369 ) 69,252 10,820 266 (10 ) 11,076 Issued by FNMA and FHLMC 714,350 2,171 (3,165 ) 713,356 96,631 286 (370 ) 96,547 Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 656,162 3,777 (1,713 ) 658,226 485,324 7,026 (656 ) 491,694 Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 113,359 625 (206 ) 113,778 109,762 1,042 (82 ) 110,722 Total $ 1,600,984 $ 7,580 $ (6,160 ) $ 1,602,404 $ 738,099 $ 9,274 $ (1,171 ) $ 746,202
Securities with Gross Unrealized Losses, Segregated by Length of Impairment	The tables below include securities with gross unrealized losses for which an allowance for credit losses has not been recorded and segregated by length of impairment at June 30, 2020 and December 31, 2019 ($ in thousands): Less than 12 Months 12 Months or More Total June 30, 2020 Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses U.S. Government agency obligations $ — $ — $ 11,624 $ (516 ) $ 11,624 $ (516 ) Obligations of states and political subdivisions — — 6,221 (25 ) 6,221 (25 ) Mortgage-backed securities Residential mortgage pass-through securities Guaranteed by GNMA 325 (1 ) — — 325 (1 ) Issued by FNMA and FHLMC 20,644 (7 ) 8,954 (12 ) 29,598 (19 ) Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 2,436 (15 ) — — 2,436 (15 ) Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA — — 668 (10 ) 668 (10 ) Total $ 23,405 $ (23 ) $ 27,467 $ (563 ) $ 50,872 $ (586 ) December 31, 2019 U.S. Government agency obligations $ 6,585 $ (105 ) $ 12,886 $ (602 ) $ 19,471 $ (707 ) Obligations of states and political subdivisions — — 6,216 (53 ) 6,216 (53 ) Mortgage-backed securities Residential mortgage pass-through securities Guaranteed by GNMA 23,544 (107 ) 18,529 (272 ) 42,073 (379 ) Issued by FNMA and FHLMC 112,879 (230 ) 278,120 (3,305 ) 390,999 (3,535 ) Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 158,341 (738 ) 151,271 (1,631 ) 309,612 (2,369 ) Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 51,312 (167 ) 14,155 (121 ) 65,467 (288 ) Total $ 352,661 $ (1,347 ) $ 481,177 $ (5,984 ) $ 833,838 $ (7,331 )
Contractual Maturities of Available for Sale and Held to Maturity Securities	The amortized cost and estimated fair value of securities available for sale and held to maturity at June 30, 2020, by contractual maturity, are shown below ($ in thousands). Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Securities Available for Sale Securities Held to Maturity Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Due in one year or less $ 7,867 $ 7,945 $ 18,599 $ 18,715 Due after one year through five years 1,559 1,601 13,030 13,350 Due after five years through ten years 2,161 2,112 — — Due after ten years 19,232 19,416 — — 30,819 31,074 31,629 32,065 Mortgage-backed securities 1,808,759 1,853,079 628,419 658,496 Total $ 1,839,578 $ 1,884,153 $ 660,048 $ 690,561

Loans Held for Investment (LH_2

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI (Tables)	6 Months Ended
	Jun. 30, 2020
Accounts Notes Loans And Financing Receivable Gross Allowance And Net [Abstract]
Loan Portfolio Held for Investment	At June 30, 2020 and December 31, 2019, LHFI consisted of the following ($ in thousands): June 30, 2020 December 31, 2019 Loans secured by real estate: Construction, land development and other land $ 482,309 $ 1,162,791 Other secured by 1-4 family residential properties 562,828 1,855,913 Secured by nonfarm, nonresidential properties 2,610,392 2,475,245 Other real estate secured 884,815 724,480 Other loans secured by real estate: (1) Other construction 794,968 — Secured by 1-4 family residential properties 1,250,697 — Commercial and industrial loans 1,413,255 1,477,896 Consumer loans 164,560 175,738 State and other political subdivision loans 931,536 967,944 Other commercial loans (1) 564,446 495,621 LHFI 9,659,806 9,335,628 Less ACL 119,188 84,277 Net LHFI $ 9,540,618 $ 9,251,351 (1) In accordance with the guidance in FASB ASC Topic 326, Trustmark redefined its LHFI portfolio segments and related loan classes based on the level at which risk is monitored within the ACL methodology. The other loans secured by real estate portfolio segment and related loan classes were separated from the loans secured by real estate portfolio segment. The other construction loans were segregated from the construction, land development and other land loans. The other loans secured by 1-4 family residential properties were segregated from the loans secured by 1-4 family residential properties and the loans secured by 1-4 family residential properties were redefined in the other loans secured by real estate portfolio segment. Other loans were redefined as other commercial loans.
Schedule of Amortized Cost Basis of Loans on Nonaccrual Status	The following table provides the amortized cost basis of loans on nonaccrual status and loans past due 90 days or more still accruing interest as of June 30, 2020 ($ in thousands): June 30, 2020 Nonaccrual With No ACL Total Nonaccrual Loans Past Due 90 Days or More Still Accruing Loans secured by real estate: Construction, land development and other land $ 575 $ 932 $ — Other secured by 1-4 family residential properties 496 4,441 51 Secured by nonfarm, nonresidential properties 5,389 7,883 — Other real estate secured 63 881 — Other loans secured by real estate: Other construction — — — Secured by 1-4 family residential properties 1,480 12,523 528 Commercial and industrial loans 16,436 18,181 — Consumer loans — 120 217 State and other political subdivision loans — 4,049 — Other commercial loans 12 984 11 Total $ 24,451 $ 49,994 $ 807
Aging Analysis of Past Due and Nonaccrual LHFI by Loan Type	The following table provides an aging analysis of the amortized cost basis of past due LHFI at June 30, 2020 ($ in thousands): June 30, 2020 Past Due 30-59 Days 60-89 Days 90 Days or Total Past Due Current Loans Total LHFI Loans secured by real estate: Construction, land development and other land $ 699 $ 323 $ 191 $ 1,213 $ 481,096 $ 482,309 Other secured by 1-4 family residential properties 1,481 1,017 632 3,130 559,698 562,828 Secured by nonfarm, nonresidential properties 187 391 682 1,260 2,609,132 2,610,392 Other real estate secured 165 — 288 453 884,362 884,815 Other loans secured by real estate: Other construction — — — — 794,968 794,968 Secured by 1-4 family residential properties 1,880 1,500 5,501 8,881 1,241,816 1,250,697 Commercial and industrial loans 594 99 2,001 2,694 1,410,561 1,413,255 Consumer loans 879 152 217 1,248 163,312 164,560 State and other political subdivision loans — — 177 177 931,359 931,536 Other commercial loans 351 16 446 813 563,633 564,446 Total $ 6,236 $ 3,498 $ 10,135 $ 19,869 $ 9,639,937 $ 9,659,806 The following table provides an aging analysis of past due and nonaccrual LHFI by loan class at December 31, 2019 ($ in thousands): December 31, 2019 Past Due 30-59 Days 60-89 Days 90 Days or (1) Total Nonaccrual Current Loans Total LHFI Loans secured by real estate: Construction, land development and other land $ 380 $ 256 $ — $ 636 $ 897 $ 1,161,258 $ 1,162,791 Secured by 1-4 family residential properties 5,254 940 211 6,405 16,810 1,832,698 1,855,913 Secured by nonfarm, nonresidential properties 1,698 — — 1,698 7,700 2,465,847 2,475,245 Other real estate secured 8 — — 8 1,032 723,440 724,480 Commercial and industrial loans 617 12 39 668 21,775 1,455,453 1,477,896 Consumer loans 2,208 380 392 2,980 108 172,650 175,738 State and other political subdivision loans 76 — — 76 4,079 963,789 967,944 Other loans 152 4 — 156 825 494,640 495,621 Total $ 10,393 $ 1,592 $ 642 $ 12,627 $ 53,226 $ 9,269,775 $ 9,335,628 (1) Past due 90 days or more but still accruing interest.
Impaired Financing Receivables	At December 31, 2019, individually evaluated impaired LHFI consisted of the following ($ in thousands): December 31, 2019 LHFI Unpaid Principal Balance With No Related Allowance Recorded With an Allowance Recorded Total Recorded Investment Related Allowance Average Recorded Investment Loans secured by real estate: Construction, land development and other land $ 926 $ 610 $ 16 $ 626 $ — $ 1,089 Secured by 1-4 family residential properties 6,513 2,104 3,360 5,464 35 4,713 Secured by nonfarm, nonresidential properties 7,295 1,462 5,255 6,717 2,355 8,096 Other real estate secured 69 — 68 68 — 158 Commercial and industrial loans 27,178 19,374 4,084 23,458 707 27,088 Consumer loans 22 — 21 21 — 11 State and other political subdivision loans 4,079 — 4,079 4,079 1,809 6,337 Other loans 1,207 — 784 784 553 1,033 Total $ 47,289 $ 23,550 $ 17,667 $ 41,217 $ 5,459 $ 48,525
Impact of Modifications Classified as Troubled Debt Restructurings	The following table illustrates the impact of modifications classified as TDRs for the periods presented ($ in thousands): Three Months Ended June 30, 2020 2019 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Loans secured by real estate: Other secured by 1-4 family residential properties 3 $ 206 $ 210 5 $ 793 $ 792 Secured by nonfarm, nonresidential properties 1 139 139 1 5,055 5,055 Commercial and industrial loans — — — 2 113 — Consumer loans 2 6 6 — — — State and other political subdivision loans 2 3,902 3,872 — — — Total 8 $ 4,253 $ 4,227 8 $ 5,961 $ 5,847 Six Months Ended June 30, 2020 2019 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Loans secured by real estate: Other secured by 1-4 family residential properties 8 $ 707 $ 711 7 $ 879 $ 878 Secured by nonfarm, nonresidential properties 1 139 139 1 5,055 5,055 Commercial and industrial loans 2 1,582 1,582 8 9,167 9,054 Consumer loans 6 26 26 2 30 30 State and other political subdivision loans 2 3,902 3,872 — — — Total 19 $ 6,356 $ 6,330 18 $ 15,131 $ 15,017
Troubled Debt Restructuring Subsequently Defaulted	The table below includes the balances at default for TDRs modified within the last 12 months for which there was a payment default during the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Number of Contracts Recorded Investment Number of Contracts Recorded Investment Loans secured by real estate: Other secured by 1-4 family residential properties 3 $ 420 1 $ 46 Secured by nonfarm, nonresidential properties 1 139 — — Commercial and industrial loans 1 82 10 7,957 Consumer loans — — 1 27 Total 5 $ 641 12 $ 8,030
Troubled Debt Restructuring Related to Loans Held for Investment by Loan Type	The following tables detail LHFI classified as TDRs by loan class at June 30, 2020 and 2019 ($ in thousands): June 30, 2020 Accruing Nonaccrual Total Loans secured by real estate: Construction, land development and other land $ — $ 14 $ 14 Other secured by 1-4 family residential properties 71 3,761 3,832 Secured by nonfarm, nonresidential properties — 3,010 3,010 Commercial and industrial loans 1,500 14,487 15,987 Consumer loans 18 21 39 State and other political subdivision loans — 3,872 3,872 Other commercial loans — 125 125 Total TDRs $ 1,589 $ 25,290 $ 26,879 June 30, 2019 Accruing Nonaccrual Total Loans secured by real estate: Construction, land development and other land $ — $ 20 $ 20 Secured by 1-4 family residential properties 50 3,563 3,613 Secured by nonfarm, nonresidential properties — 5,311 5,311 Commercial and industrial loans 14,897 11,965 26,862 Consumer loans — 30 30 Other loans — 510 510 Total TDRs $ 14,947 $ 21,399 $ 36,346
Schedule of Amortized Cost Basis of Collateral-Dependent Loans	The following table presents the amortized cost basis of collateral-dependent loans by class of loans and collateral type as of June 30, 2020 ($ in thousands): June 30, 2020 Real Estate Equipment and Machinery Inventory and Receivables Vehicles Miscellaneous Total Loans secured by real estate: Construction, land development and other land $ 1,948 $ — $ — $ — $ — $ 1,948 Other secured by 1-4 family residential properties 496 — — — — 496 Secured by nonfarm, nonresidential properties 11,966 — — — — 11,966 Other real estate secured 63 — — — — 63 Other loans secured by real estate: Other construction — — — — — — Secured by 1-4 family residential properties 1,480 — — — — 1,480 Commercial and industrial loans 105 840 6,439 186 8,794 16,364 Consumer loans — — — — — — State and other political subdivision loans 4,049 — — — — 4,049 Other commercial loans 623 — 2,021 — 3,120 5,764 Total $ 20,730 $ 840 $ 8,460 $ 186 $ 11,914 $ 42,130
Carrying Amount of Loans by Credit Quality Indicator	The tables below present the amortized cost basis of loans by credit quality indicator and class of loans based on the most recent analysis performed ($ in thousands): Term Loans by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Total As of June 30, 2020 Commercial LHFI Loans secured by real estate: Construction, land development and other land: Pass - RR 1 through RR 6 $ 170,118 $ 146,424 $ 36,674 $ 5,413 $ 3,571 $ 5,192 $ 37,106 $ 404,498 Special Mention - RR 7 — — — — — — — — Substandard - RR 8 2,417 74 495 47 680 26 — 3,739 Doubtful - RR 9 — — — — — 42 — 42 Total 172,535 146,498 37,169 5,460 4,251 5,260 37,106 408,279 Other secured by 1-4 family residential properties: Pass - RR 1 through RR 6 $ 21,491 $ 28,901 $ 22,057 $ 11,956 $ 14,141 $ 8,565 $ 7,010 $ 114,121 Special Mention - RR 7 — 90 — — — — — 90 Substandard - RR 8 4,694 299 1,032 240 71 790 — 7,126 Doubtful - RR 9 33 1 — — — — — 34 Total 26,218 29,291 23,089 12,196 14,212 9,355 7,010 121,371 Secured by nonfarm, nonresidential properties: Pass - RR 1 through RR 6 $ 315,293 $ 519,415 $ 466,036 $ 384,595 $ 332,457 $ 424,260 $ 108,032 $ 2,550,088 Special Mention - RR 7 — 5,655 1,083 — 350 4,894 — 11,982 Substandard - RR 8 8,866 10,821 1,827 3,586 9,131 12,583 921 47,735 Doubtful - RR 9 57 180 — — — 331 — 568 Total 324,216 536,071 468,946 388,181 341,938 442,068 108,953 2,610,373 Other real estate secured: Pass - RR 1 through RR 6 $ 67,416 $ 181,243 $ 295,676 $ 160,526 $ 130,810 $ 35,183 $ 10,314 $ 881,168 Special Mention - RR 7 — — — — — 874 — 874 Substandard - RR 8 1,201 187 18 — 63 715 — 2,184 Doubtful - RR 9 — — — — — — — — Total 68,617 181,430 295,694 160,526 130,873 36,772 10,314 884,226 Term Loans by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Total As of June 30, 2020 Commercial LHFI Other loans secured by real estate: Other construction Pass - RR 1 through RR 6 $ 63,346 $ 448,004 $ 235,925 $ 25,957 $ 1,481 $ — $ 6,858 $ 781,571 Special Mention - RR 7 — — — — — — — — Substandard - RR 8 13,397 — — — — — — 13,397 Doubtful - RR 9 — — — — — — — — Total 76,743 448,004 235,925 25,957 1,481 — 6,858 794,968 Commercial and industrial loans: Pass - RR 1 through RR 6 $ 301,484 $ 281,419 $ 115,890 $ 95,696 $ 82,537 $ 56,802 $ 434,958 $ 1,368,786 Special Mention - RR 7 850 — — — — — 833 1,683 Substandard - RR 8 10,630 2,512 15,481 344 628 2,581 10,089 42,265 Doubtful - RR 9 48 402 — — 43 4 24 521 Total 313,012 284,333 131,371 96,040 83,208 59,387 445,904 1,413,255 State and other political subdivision loans: Pass - RR 1 through RR 6 $ 85,513 $ 109,844 $ 54,240 $ 119,532 $ 144,165 $ 408,276 $ 898 $ 922,468 Special Mention - RR 7 — — — — — 4,000 — 4,000 Substandard - RR 8 — — — 339 — 4,729 — 5,068 Doubtful - RR 9 — — — — — — — — Total 85,513 109,844 54,240 119,871 144,165 417,005 898 931,536 Other commercial loans: Pass - RR 1 through RR 6 $ 66,388 $ 83,965 $ 28,885 $ 14,821 $ 57,952 $ 54,114 $ 224,792 $ 530,917 Special Mention - RR 7 7,917 — — — — — 11,833 19,750 Substandard - RR 8 98 2,190 686 45 1,063 1 9,670 13,753 Doubtful - RR 9 — 3 — — — 23 — 26 Total 74,403 86,158 29,571 14,866 59,015 54,138 246,295 564,446 Total commercial LHFI $ 1,141,257 $ 1,821,629 $ 1,276,005 $ 823,097 $ 779,143 $ 1,023,985 $ 863,338 $ 7,728,454 Term Loans by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Total As of June 30, 2020 Consumer LHFI Loans secured by real estate: Construction, land development and other land: Current $ 15,175 $ 39,837 $ 10,387 $ 2,398 $ 1,784 $ 3,955 $ — $ 73,536 Past due 30-89 days — — 323 — — 45 — 368 Past due 90 days or more — — — — — — — — Nonaccrual — — — — 19 107 — 126 Total 15,175 39,837 10,710 2,398 1,803 4,107 — 74,030 Other secured by 1-4 family residential properties: Current $ 11,365 $ 19,349 $ 14,814 $ 4,464 $ 2,697 $ 16,646 $ 367,313 $ 436,648 Past due 30-89 days — 210 162 — 58 155 914 1,499 Past due 90 days or more — — — — — 13 38 51 Nonaccrual — 35 144 470 — 564 2,046 3,259 Total 11,365 19,594 15,120 4,934 2,755 17,378 370,311 441,457 Secured by nonfarm, nonresidential properties: Current $ — $ — $ — $ 5 $ — $ 14 $ — $ 19 Past due 30-89 days — — — — — — — — Past due 90 days or more — — — — — — — — Nonaccrual — — — — — — — — Total — — — 5 — 14 — 19 Other real estate secured: Current $ 91 $ — $ 44 $ 46 $ 106 $ 302 $ — $ 589 Past due 30-89 days — — — — — — — — Past due 90 days or more — — — — — — — — Nonaccrual — — — — — — — — Total 91 — 44 46 106 302 — 589 Term Loans by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Total As of June 30, 2020 Consumer LHFI Other loans secured by real estate: Secured by 1-4 family residential properties Current $ 137,146 $ 242,961 $ 218,993 $ 115,354 $ 130,831 $ 390,425 $ — $ 1,235,710 Past due 30-89 days 73 85 77 123 79 1,497 — 1,934 Past due 90 days or more — — — 139 — 390 — 529 Nonaccrual 44 713 2,507 467 558 8,235 — 12,524 Total 137,263 243,759 221,577 116,083 131,468 400,547 — 1,250,697 Consumer loans: Current $ 38,008 $ 42,705 $ 21,144 $ 7,161 $ 2,069 $ 864 $ 51,259 $ 163,210 Past due 30-89 days 219 330 129 3 — 5 326 1,012 Past due 90 days or more 28 4 11 1 — — 174 218 Nonaccrual 6 22 69 19 3 — 1 120 Total 38,261 43,061 21,353 7,184 2,072 869 51,760 164,560 Total consumer LHFI $ 202,155 $ 346,251 $ 268,804 $ 130,650 $ 138,204 $ 423,217 $ 422,071 $ 1,931,352 Total LHFI $ 1,343,412 $ 2,167,880 $ 1,544,809 $ 953,747 $ 917,347 $ 1,447,202 $ 1,285,409 $ 9,659,806 The table below presents LHFI by loan class and credit quality indicator at December 31, 2019 ($ in thousands): December 31, 2019 Commercial LHFI Pass - Categories 1-6 Special Mention - Category 7 Substandard Category 8 Doubtful - Category 9 Subtotal Loans secured by real estate: Construction, land development and other land $ 1,075,146 $ — $ 15,726 $ 42 $ 1,090,914 Secured by 1-4 family residential properties 116,592 45 6,355 41 123,033 Secured by nonfarm, nonresidential properties 2,430,761 — 44,001 328 2,475,090 Other real estate secured 721,238 — 2,547 — 723,785 Commercial and industrial loans 1,407,837 909 68,262 888 1,477,896 Consumer loans — — — — — State and other political subdivision loans 957,948 4,650 5,346 — 967,944 Other loans 469,095 3,445 16,926 30 489,496 Total $ 7,178,617 $ 9,049 $ 159,163 $ 1,329 $ 7,348,158 Consumer LHFI Current Past Due 30-89 Days Past Due 90 Days or More Nonaccrual Subtotal Total LHFI Loans secured by real estate: Construction, land development and other land $ 71,413 $ 332 $ — $ 132 $ 71,877 $ 1,162,791 Secured by 1-4 family residential properties 1,710,930 5,922 211 15,817 1,732,880 1,855,913 Secured by nonfarm, nonresidential properties 155 — — — 155 2,475,245 Other real estate secured 695 — — — 695 724,480 Commercial and industrial loans — — — — — 1,477,896 Consumer loans 172,649 2,588 393 108 175,738 175,738 State and other political subdivision loans — — — — — 967,944 Other loans 6,125 — — — 6,125 495,621 Total $ 1,961,967 $ 8,842 $ 604 $ 16,057 $ 1,987,470 $ 9,335,628
Summary of Trustmark's Portfolio Segments, Loan Classes, Loan Pools and the ACL Methodology and Loss Drivers	The following table provides a description of each of Trustmark’s portfolio segments, loan classes, loan pools and the ACL methodology and loss drivers: Portfolio Segment Loan Class Loan Pool Methodology Loss Drivers Loans secured by real estate Construction, land development and other land 1-4 family residential construction DCF Prime Rate, National GDP Lots and development DCF Prime Rate, Southern Unemployment Unimproved land DCF Prime Rate, Southern Unemployment All other consumer DCF Prime Rate, Southern Unemployment Other secured by 1-4 family residential properties Consumer 1-4 family - 1st liens DCF Prime Rate, Southern Unemployment All other consumer DCF Prime Rate, Southern Unemployment Nonresidential owner-occupied DCF Southern Unemployment, National GDP Secured by nonfarm, nonresidential properties Nonowner-occupied - hotel/motel DCF Southern Vacancy Rate, Southern Unemployment Nonowner-occupied - office DCF Southern Vacancy Rate, Southern Unemployment Nonowner-occupied- Retail DCF Southern Vacancy Rate, Southern Unemployment Nonowner-occupied - senior living/nursing homes DCF Southern Vacancy Rate, Southern Unemployment Nonowner-occupied - all other DCF Southern Vacancy Rate, Southern Unemployment Nonresidential owner-occupied DCF Southern Unemployment, National GDP Other real estate secured Nonresidential nonowner -occupied - apartments DCF Southern Vacancy Rate, Southern Unemployment Nonresidential owner-occupied DCF Southern Unemployment, National GDP Nonowner-occupied - all other DCF Southern Vacancy Rate, Southern Unemployment Other loans secured by real estate Other construction Other construction WARM Prime Rate, National Unemployment Secured by 1-4 family residential properties Trustmark mortgage WARM Southern Unemployment Commercial and industrial loans Commercial and industrial loans Commercial and industrial - non-working capital DCF Trustmark historical data Commercial and industrial - working capital DCF Trustmark historical data Credit cards WARM Trustmark call report data Consumer loans Consumer loans Credit cards WARM Trustmark call report data Overdrafts Loss Rate Trustmark historical data All other consumer DCF Prime Rate, Southern Unemployment State and other political subdivision loans State and other political subdivision loans Obligations of state and political subdivisions DCF Moody's Bond Default Study Other commercial loans Other commercial loans Other loans DCF Prime Rate, Southern Unemployment Commercial and industrial - non-working capital DCF Trustmark historical data Commercial and industrial - working capital DCF Trustmark historical data
Change in Allowance for Loan Losses	The following table disaggregates the ACL and the amortized cost basis of the loans by the measurement methodology used at June 30, 2020 ($ in thousands): June 30, 2020 ACL LHFI Individually Evaluated for Credit Loss Collectively Evaluated for Credit Loss Total ACL Individually Evaluated for Credit Loss Collectively Evaluated for Credit Loss Total LHFI Loans secured by real estate: Construction, land development and other land $ — $ 11,940 $ 11,940 $ 1,948 480,361 $ 482,309 Other secured by 1-4 family residential properties — 12,716 12,716 496 562,332 562,828 Secured by nonfarm, nonresidential properties — 36,417 36,417 11,966 2,598,426 2,610,392 Other real estate secured — 7,600 7,600 63 884,752 884,815 Other loans secured by real estate: Other construction — 10,803 10,803 — 794,968 794,968 Secured by 1-4 family residential properties — 10,899 10,899 1,480 1,249,217 1,250,697 Commercial and industrial loans 21 12,529 12,550 16,363 1,396,892 1,413,255 Consumer loans — 6,397 6,397 — 164,560 164,560 State and other political subdivision loans 1,779 1,635 3,414 4,049 927,487 931,536 Other commercial loans 518 5,934 6,452 5,764 558,682 564,446 Total $ 2,318 $ 116,870 $ 119,188 $ 42,129 $ 9,617,677 $ 9,659,806 The following table disaggregates the allowance for loan losses and LHFI balances by the impairment evaluation methodology used at December 31, 2019 ($ in thousands): December 31, 2019 Allowance for Loan Losses LHFI Individually Evaluated Collectively Evaluated Total Individually Evaluated Collectively Evaluated Total Loans secured by real estate: Construction, land development and other land $ — $ 8,260 $ 8,260 $ 626 $ 1,162,165 $ 1,162,791 Secured by 1-4 family residential properties 35 8,897 8,932 5,464 1,850,449 1,855,913 Secured by nonfarm, nonresidential properties 2,355 23,803 26,158 6,717 2,468,528 2,475,245 Other real estate secured — 4,024 4,024 68 724,412 724,480 Commercial and industrial loans 707 25,285 25,992 23,458 1,454,438 1,477,896 Consumer loans — 3,379 3,379 21 175,717 175,738 State and other political subdivision loans 1,809 420 2,229 4,079 963,865 967,944 Other loans 553 4,750 5,303 784 494,837 495,621 Total $ 5,459 $ 78,818 $ 84,277 $ 41,217 $ 9,294,411 $ 9,335,628 Changes in the ACL were as follows for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Balance at beginning of period $ 100,564 $ 79,005 $ 84,277 $ 79,290 FASB ASU 2016-13 adoption adjustments: LHFI — — (3,039 ) — Allowance for loan losses, acquired loans transfer — — 815 — Acquired loans ACL adjustment — — 1,007 — Loans charged-off (1,870 ) (2,937 ) (7,415 ) (6,970 ) Recoveries 2,309 1,845 4,777 3,982 Net (charge-offs) recoveries 439 (1,092 ) (2,638 ) (2,988 ) PCL 18,185 2,486 38,766 4,097 Balance at end of period $ 119,188 $ 80,399 $ 119,188 $ 80,399 The following table details changes in the ACL by loan class for the period presented ($ in thousands): Three Months Ended June 30, 2020 Balance at Beginning of Period Charge-offs Recoveries PCL Balance at End of Period Loans secured by real estate: Construction, land development and other land $ 9,079 $ (7 ) $ 92 $ 2,776 $ 11,940 Other secured by 1-4 family residential properties 11,711 (36 ) 83 958 12,716 Secured by nonfarm, nonresidential properties 28,127 — 445 7,845 36,417 Other real estate secured 5,273 — 12 2,315 7,600 Other loans secured by real estate: Other construction 7,711 — 21 3,071 10,803 Secured by 1-4 family residential properties 8,042 — 13 2,844 10,899 Commercial and industrial loans 14,564 (297 ) 191 (1,908 ) 12,550 Consumer loans 6,596 (671 ) 468 4 6,397 State and other political subdivision loans 3,441 — — (27 ) 3,414 Other commercial loans 6,020 (859 ) 984 307 6,452 Total $ 100,564 $ (1,870 ) $ 2,309 $ 18,185 $ 119,188 The increases in the PCL for loans and other loans secured by real estate during the three months ended June 30, 2020 were primarily due to the negative impact of COVID-19 on the macroeconomic forecasting variables used in the ACL modeling, such as National and Southern Unemployment, National GDP, Prime Rate and South Vacancy Rate. The PCL for the commercial and industrial loan portfolio decreased $1.9 million during the three months ended June 30, 2020 primarily due to upgrades on loans from substandard to pass, paydowns and a slight decrease in the calculated PD and LGD, which uses Trustmark’s historical data. The following table details changes in the ACL by loan class for the period presented ($ in thousands): Six Months Ended June 30, 2020 Balance at Beginning of Period FASB ASU 2016-13 Adoption Adjustment Charge-offs Recoveries PCL Balance at End of Period Loans secured by real estate: Construction, land development and other land $ 6,371 $ (188 ) $ (7 ) $ 186 $ 5,578 $ 11,940 Other secured by 1-4 family residential properties 5,888 4,188 (100 ) 146 2,594 12,716 Secured by nonfarm, nonresidential properties 26,158 (8,179 ) (2,448 ) 506 20,380 36,417 Other real estate secured 4,024 (765 ) (8 ) 18 4,331 7,600 Other loans secured by real estate: Other construction 1,889 3,202 — 40 5,672 10,803 Secured by 1-4 family residential properties 3,044 2,891 (19 ) 106 4,877 10,899 Commercial and industrial loans 25,992 (8,964 ) (1,279 ) 733 (3,932 ) 12,550 Consumer loans 3,379 2,059 (1,361 ) 941 1,379 6,397 State and other political subdivision loans 2,229 2,455 — — (1,270 ) 3,414 Other commercial loans 5,303 2,084 (2,193 ) 2,101 (843 ) 6,452 Total $ 84,277 $ (1,217 ) $ (7,415 ) $ 4,777 $ 38,766 $ 119,188 The following table details changes in the allowance for loan losses, LHFI by loan class for the period presented ($ in thousands): 2019 Balance January 1, Charge-offs Recoveries Provision for Loan Losses Balance June 30, Loans secured by real estate: Construction, land development and other land loans $ 7,390 $ (35 ) $ 577 $ (1,001 ) $ 6,931 Secured by 1-4 family residential properties 8,641 (281 ) 336 (337 ) 8,359 Secured by nonfarm, nonresidential properties 22,376 (34 ) 30 1,876 24,248 Other real estate secured 3,450 — 16 255 3,721 Commercial and industrial loans 27,359 (2,831 ) 329 2,761 27,618 Consumer loans 2,890 (1,269 ) 954 673 3,248 State and other political subdivision loans 990 — — (552 ) 438 Other loans 6,194 (2,520 ) 1,740 422 5,836 Total $ 79,290 $ (6,970 ) $ 3,982 $ 4,097 $ 80,399

Acquired Loans (Tables)

Acquired Loans (Tables)	6 Months Ended
	Jun. 30, 2020
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities [Abstract]
Schedule of Acquired Loans	At December 31, 2019, acquired loans consisted of the following ($ in thousands): December 31, 2019 Loans secured by real estate: Construction, land development and other land $ 4,771 Secured by 1-4 family residential properties 17,525 Secured by nonfarm, nonresidential properties 38,206 Other real estate secured 3,946 Commercial and industrial loans 5,035 Consumer loans 520 Other loans 2,598 Acquired loans 72,601 Less allowance for loan losses, acquired loans 815 Net acquired loans $ 71,786
Changes in the Carrying Value of Acquired Loans	The following table presents changes in the net carrying value of the acquired loans for the periods presented ($ in thousands): Acquired Impaired Acquired Not ASC 310-30 (1) Carrying value, net at January 1, 2019 $ 102,890 $ 2,811 Transfers (2) — (2,926 ) Accretion to interest income 5,532 115 Payments received, net (37,230 ) — Other (3) 178 — Change in allowance for loan losses, acquired loans 416 — Carrying value, net at December 31, 2019 71,786 — FASB ASU 2016-13 adoption adjustment (71,786 ) — Accretion to interest income — — Payments received, net — — Other (3) — — Change in allowance for loan losses, acquired loans — — Carrying value, net at June 30, 2020 $ — $ — (1) “Acquired Not ASC 310-30” loans consist of loans that are not in scope for FASB ASC Subtopic 310-30. (2) “Acquired Not ASC 310-30” ( 3 ) Includes miscellaneous timing adjustments as well as acquired loan terminations through foreclosure, charge-off and other terminations.
Changes in Accretable Yield of Acquired Loans	The following table presents changes in the accretable yield for the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Accretable yield at beginning of period $ (14,816 ) $ (17,722 ) FASB ASU 2016-13 adoption adjustment 14,816 — Accretion to interest income — 2,983 Disposals, net — 1,114 Reclassification from nonaccretable difference (1) — (2,280 ) Accretable yield at end of period $ — $ (15,905 ) (1) Reclassifications from nonaccretable difference are due to lower loss expectations and improvements in expected cash flows.
Components of the Allowance for Loan Losses on Acquired Loans	The following table presents the components of the allowance for loan losses on acquired loans for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Balance at beginning of period $ — $ 1,297 $ 815 $ 1,231 FASB ASU 2016-13 adoption adjustment — — (815 ) — Net (charge-offs) recoveries — (5 ) — (17 ) Provision for loan losses, acquired loans — 106 — 184 Balance at end of period $ — $ 1,398 $ — $ 1,398
Acquired Loans by Loan Class and Credit Quality Indicator	The table below presents the acquired loans by loan class and credit quality indicator at December 31, 2019 ($ in thousands): December 31, 2019 Commercial Loans Pass - Categories 1-6 Special Mention - Category 7 Substandard - Category 8 Doubtful - Category 9 Subtotal Loans secured by real estate: Construction, land development and other land $ 4,022 $ — $ 192 $ — $ 4,214 Secured by 1-4 family residential properties 3,164 42 580 — 3,786 Secured by nonfarm, nonresidential properties 27,848 — 9,972 386 38,206 Other real estate secured 3,878 — 68 0 3,946 Commercial and industrial loans 3,419 — — 1,616 5,035 Consumer loans — — — — — Other loans 2,591 — 7 — 2,598 Total acquired loans $ 44,922 $ 42 $ 10,819 $ 2,002 $ 57,785 Consumer Loans Current Past Due 30-89 Days Past Due 90 Days or More Nonaccrual (1) Subtotal Total Acquired Loans Loans secured by real estate: Construction, land development and other land $ 463 $ 94 $ — $ — $ 557 $ 4,771 Secured by 1-4 family residential properties 12,843 615 281 — 13,739 17,525 Secured by nonfarm, nonresidential properties — — — — — 38,206 Other real estate secured — — — — — 3,946 Commercial and industrial loans — — — — — 5,035 Consumer loans 489 31 — — 520 520 Other loans — — — — — 2,598 Total acquired loans $ 13,795 $ 740 $ 281 $ — $ 14,816 $ 72,601 (1) Acquired loans not accounted for under FASB ASC Subtopic 310-30.
Aging Analysis of Past Due and Nonaccrual Acquired Loans	The following table provides an aging analysis of contractually past due and nonaccrual acquired loans at December 31, 2019 ($ in thousands): December 31, 2019 Past Due 30-59 Days 60-89 Days 90 Days or More (1) Total Nonaccrual (2) Current Loans Total Acquired Loans Loans secured by real estate: Construction, land development and other land $ 94 $ — $ 38 $ 132 $ — $ 4,639 $ 4,771 Secured by 1-4 family residential properties 696 131 366 1,193 — 16,332 17,525 Secured by nonfarm, nonresidential properties 36 — 851 887 — 37,319 38,206 Other real estate secured 1 — 52 53 — 3,893 3,946 Commercial and industrial loans — — — — — 5,035 5,035 Consumer loans 16 15 — 31 — 489 520 Other loans — — — — — 2,598 2,598 Total acquired loans $ 843 $ 146 $ 1,307 $ 2,296 $ — $ 70,305 $ 72,601 (1) Past due 90 days or more but still accruing interest. (2) Acquired loans not accounted for under FASB ASC Subtopic 310-30.

Mortgage Banking (Tables)

Mortgage Banking (Tables)	6 Months Ended
	Jun. 30, 2020
Mortgage Banking [Abstract]
Schedule of Activity in the Mortgage Servicing Rights	The activity in the mortgage servicing rights (MSR) is detailed in the table below for the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Balance at beginning of period $ 79,394 $ 95,596 Origination of servicing assets 12,396 6,075 Change in fair value: Due to market changes (27,158 ) (17,072 ) Due to run-off (6,821 ) (5,316 ) Balance at end of period $ 57,811 $ 79,283
Schedule of Mortgage Loans Sold and Serviced for Others	The table below details the mortgage loans sold and serviced for others at June 30, 2020 and December 31, 2019 ($ in thousands): June 30, 2020 December 31, 2019 Federal National Mortgage Association $ 4,535,557 $ 4,411,914 Government National Mortgage Association 2,774,839 2,652,782 Federal Home Loan Mortgage Corporation 64,232 73,134 Other 18,012 19,404 Total mortgage loans sold and serviced for others $ 7,392,640 $ 7,157,234

Other Real Estate (Tables)

Other Real Estate (Tables)	6 Months Ended
	Jun. 30, 2020
Other Real Estate And Foreclosed Assets [Abstract]
Changes and Gains (Losses), Net on Other Real Estate	For the periods presented, changes and gains (losses), net on other real estate were as follows ($ in thousands): Six Months Ended June 30, 2020 2019 Balance at beginning of period $ 29,248 $ 34,668 Additions 406 2,101 Disposals (10,534 ) (3,859 ) Write-downs (844 ) (1,667 ) Balance at end of period $ 18,276 $ 31,243 Gains (losses), net on the sale of other real estate included in other real estate expense $ (255 ) $ 246
Other Real Estate, By Type of Property	At June 30, 2020 and December 31, 2019, other real estate by type of property consisted of the following ($ in thousands): June 30, 2020 December 31, 2019 Construction, land development and other land properties $ 8,341 $ 11,482 1-4 family residential properties 1,992 3,453 Nonfarm, nonresidential properties 7,943 14,313 Total other real estate $ 18,276 $ 29,248
Other Real Estate, By Geographic Location	At June 30, 2020 and December 31, 2019, other real estate by geographic location consisted of the following ($ in thousands): June 30, 2020 December 31, 2019 Alabama $ 4,766 $ 8,133 Florida 3,665 5,877 Mississippi (1) 9,408 14,919 Tennessee (2) 437 319 Texas — — Total other real estate $ 18,276 $ 29,248 (1) Mississippi includes Central and Southern Mississippi Regions. (2) Tennessee includes Memphis, Tennessee and Northern Mississippi Regions.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Components of Net Lease Cost	The following table details the components of net lease cost for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Finance leases Amortization of right-of-use assets $ 481 $ 642 $ 978 $ 1,145 Interest on lease liabilities 65 80 132 161 Operating lease cost 1,289 1,289 2,579 2,589 Short-term lease cost 111 123 220 203 Variable lease cost 332 346 679 690 Sublease income (63 ) (82 ) (162 ) (169 ) Net lease cost $ 2,215 $ 2,398 $ 4,426 $ 4,619
Cash Payments Included in Measurement of Lease Liabilities	The following table details the cash payments included in the measurement of lease liabilities during the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Finance leases Operating cash flows included in operating activities $ 132 $ 526 Financing cash flows included in payments under finance lease obligations 905 1,035 Operating leases Operating cash flows (fixed payments) included in other operating activities, net 2,493 2,481 Operating cash flows (liability reduction) included in other operating activities, net 1,949 1,875
Balance Sheet Information and Weighted-Average Lease Terms and Discount Rates Related to Leases	The following table details balance sheet information, as well as weighted-average lease terms and discount rates, related to leases at June 30, 2020 and December 31, 2019 ($ in thousands): June 30, 2020 December 31, 2019 Finance lease right-of-use assets, net of accumulated depreciation $ 8,348 $ 9,326 Finance lease liabilities 8,616 9,520 Operating lease right-of-use assets 29,819 31,182 Operating lease liabilities 31,076 32,354 Weighted-average lease term Finance leases 8.58 years 8.62 years Operating leases 8.72 years 9.05 years Weighted-average discount rate Finance leases 3.05 % 3.01 % Operating leases 3.49 % 3.51 %
Future Minimum Rental Commitments Under Finance and Operating Leases	At June 30, 2020, future minimum rental commitments under finance and operating leases were as follows ($ in thousands): Finance Leases Operating Leases 2020 (excluding the six months ended June 30, 2020) $ 1,740 $ 4,890 2021 1,617 4,355 2022 1,350 4,139 2023 549 4,102 2024 582 3,994 Thereafter 4,161 14,738 Total minimum lease payments 9,999 36,218 Less imputed interest (1,383 ) (5,142 ) Lease liabilities $ 8,616 $ 31,076

Deposits (Tables)

Deposits (Tables)	6 Months Ended
	Jun. 30, 2020
Deposits [Abstract]
Deposits Summary	At June 30, 2020 and December 31, 2019, deposits consisted of the following ($ in thousands): June 30, 2020 December 31, 2019 Noninterest-bearing demand $ 3,880,540 $ 2,891,215 Interest-bearing demand 4,037,460 3,125,914 Savings 4,075,127 3,590,509 Time 1,512,346 1,637,919 Total $ 13,505,473 $ 11,245,557

Securities Sold Under Repurch_2

Securities Sold Under Repurchase Agreements (Tables)	6 Months Ended
	Jun. 30, 2020
Securities Sold Under Agreements To Repurchase [Abstract]
Schedule of Securities Sold Under Repurchase Agreements	The following table presents the securities sold under repurchase agreements by collateral pledged at June 30, 2020 and December 31, 2019 ($ in thousands): June 30, 2020 December 31, 2019 Mortgage-backed securities Other residential mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA $ 23,780 $ 24,282 Commercial mortgage-backed securities Issued or guaranteed by FNMA, FHLMC or GNMA 29,742 29,290 Total securities sold under repurchase agreements $ 53,522 $ 53,572

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	6 Months Ended
	Jun. 30, 2020
Revenue From Contract With Customer [Abstract]
Summary of Noninterest Income Disaggregated by Reportable Operating Segment and Revenue Stream	The following tables present noninterest income disaggregated by reportable operating segment and revenue stream for the periods presented ($ in thousands): Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Topic 606 Not Topic 606 (1) Total Topic 606 Not Topic 606 (1) Total General Banking Segment Service charges on deposit accounts $ 6,380 $ — $ 6,380 $ 10,357 $ — $ 10,357 Bank card and other fees 6,549 1,160 7,709 7,162 823 7,985 Mortgage banking, net — 33,745 33,745 — 10,295 10,295 Wealth management 79 — 79 97 — 97 Other, net 1,354 784 2,138 2,333 (259 ) 2,074 Total noninterest income $ 14,362 $ 35,689 $ 50,051 $ 19,949 $ 10,859 $ 30,808 Wealth Management Segment Service charges on deposit accounts $ 17 $ — $ 17 $ 22 $ — $ 22 Bank card and other fees 8 — 8 19 — 19 Wealth management 7,492 — 7,492 7,645 — 7,645 Other, net 24 9 33 25 29 54 Total noninterest income $ 7,541 $ 9 $ 7,550 $ 7,711 $ 29 $ 7,740 Insurance Segment Insurance commissions $ 11,868 $ — $ 11,868 $ 11,089 $ — $ 11,089 Other, net 42 — 42 2 — 2 Total noninterest income $ 11,910 $ — $ 11,910 $ 11,091 $ — $ 11,091 Consolidated Service charges on deposit accounts $ 6,397 $ — $ 6,397 $ 10,379 $ — $ 10,379 Bank card and other fees 6,557 1,160 7,717 7,181 823 8,004 Mortgage banking, net — 33,745 33,745 — 10,295 10,295 Insurance commissions 11,868 — 11,868 11,089 — 11,089 Wealth management 7,571 — 7,571 7,742 — 7,742 Other, net 1,420 793 2,213 2,360 (230 ) 2,130 Total noninterest income $ 33,813 $ 35,698 $ 69,511 $ 38,751 $ 10,888 $ 49,639 (1) Noninterest income not in scope for FASB ASC Topic 606 includes customer derivatives revenue and miscellaneous credit card fee income within bank card and other fees; mortgage banking, net; amortization of tax credits, accretion of the FDIC indemnification asset, cash surrender value on various life insurance policies, earnings on Trustmark’s non-qualified deferred compensation plans, other partnership investments and rental income within other, net; and security Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Topic 606 Not Topic 606 (1) Total Topic 606 Not Topic 606 (1) Total General Banking Segment Service charges on deposit accounts $ 16,392 $ — $ 16,392 $ 20,597 $ — $ 20,597 Bank card and other fees 13,275 (217 ) 13,058 14,027 1,125 15,152 Mortgage banking, net — 61,228 61,228 — 13,737 13,737 Wealth management 165 — 165 188 — 188 Other, net 3,118 1,266 4,384 4,577 (530 ) 4,047 Total noninterest income $ 32,950 $ 62,277 $ 95,227 $ 39,389 $ 14,332 $ 53,721 Wealth Management Segment Service charges on deposit accounts $ 37 $ — $ 37 $ 47 $ — $ 47 Bank card and other fees 14 — 14 43 — 43 Wealth management 15,943 — 15,943 15,037 — 15,037 Other, net 50 22 72 261 55 316 Total noninterest income $ 16,044 $ 22 $ 16,066 $ 15,388 $ 55 $ 15,443 Insurance Segment Insurance commissions $ 23,418 $ — $ 23,418 $ 21,960 $ — $ 21,960 Other, net 64 — 64 6 — 6 Total noninterest income $ 23,482 $ — $ 23,482 $ 21,966 $ — $ 21,966 Consolidated Service charges on deposit accounts $ 16,429 $ — $ 16,429 $ 20,644 $ — $ 20,644 Bank card and other fees 13,289 (217 ) 13,072 14,070 1,125 15,195 Mortgage banking, net — 61,228 61,228 — 13,737 13,737 Insurance commissions 23,418 — 23,418 21,960 — 21,960 Wealth management 16,108 — 16,108 15,225 — 15,225 Other, net 3,232 1,288 4,520 4,844 (475 ) 4,369 Total noninterest income $ 72,476 $ 62,299 $ 134,775 $ 76,743 $ 14,387 $ 91,130 (1) Noninterest income not in scope for FASB ASC Topic 606 includes customer derivatives revenue and miscellaneous credit card fee income within bank card and other fees; mortgage banking, net; amortization of tax credits, accretion of the FDIC indemnification asset, cash surrender value on various life insurance policies, earnings on Trustmark’s non-qualified deferred compensation plans, other partnership investments and rental income within other, net; and security

Defined Benefit and Other Pos_2

Defined Benefit and Other Postretirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2020
Trustmark Capital Accumulation Plan [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Benefit Cost	The following table presents information regarding the net periodic benefit cost for the Continuing Plan for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Service cost $ 63 $ 53 $ 127 $ 106 Interest cost 61 90 121 180 Expected return on plan assets (39 ) (50 ) (77 ) (101 ) Recognized net loss due to lump sum settlements 40 63 40 94 Recognized net actuarial loss 82 93 163 186 Net periodic benefit cost $ 207 $ 249 $ 374 $ 465
Supplemental Retirement Plan [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Benefit Cost	The following table presents information regarding the net periodic benefit cost for Trustmark’s nonqualified supplemental retirement plans for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Service cost $ 20 $ 28 $ 39 $ 55 Interest cost 387 501 801 1,042 Amortization of prior service cost 38 62 75 125 Recognized net actuarial loss 236 154 482 316 Net periodic benefit cost $ 681 $ 745 $ 1,397 $ 1,538

Stock and Incentive Compensat_2

Stock and Incentive Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Plan Activity	The following tables summarize the Stock Plan activity for the periods presented: Three Months Ended June 30, 2020 Performance Awards and Units Time-Vested Awards and Units Nonvested shares, beginning of period 147,533 329,732 Granted — 6,040 Released from restriction — (28,065 ) Forfeited (1,025 ) (3,014 ) Nonvested shares, end of period 146,508 304,693 Six Months Ended June 30, 2020 Performance Awards and Units Time-Vested Awards and Units Nonvested shares, beginning of period 149,914 300,006 Granted 53,450 121,560 Released from restriction (36,357 ) (107,506 ) Forfeited (20,499 ) (9,367 ) Nonvested shares, end of period 146,508 304,693
Compensation Expense for Awards and Units Under Stock Plan	The following table presents information regarding compensation expense for awards and units under the Stock Plan for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Performance awards and units $ 456 $ 481 $ (57 ) $ 562 Time-vested awards and units 818 798 2,725 1,719 Total compensation expense $ 1,274 $ 1,279 $ 2,668 $ 2,281

Contingencies (Tables)

Contingencies (Tables)	6 Months Ended
	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Summary of Changes in ACL on Off-balance Sheet Credit Exposures	Changes in the ACL on off-balance sheet credit exposures were as follows for the periods presented ($ in thousands): Three Months Ended Six Months Ended June 30, 2020 June 30, 2020 Balance at beginning of period $ 36,421 $ — FASB ASU 2016-13 adoption adjustment — 29,638 Credit loss expense related to off-balance sheet credit exposures 6,242 13,025 Balance at end of period $ 42,663 $ 42,663

Earnings Per Share (EPS) (Table

Earnings Per Share (EPS) (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Weighted-Average Shares Used to Calculate Basic and Diluted EPS	The following table reflects weighted-average shares used to calculate basic and diluted EPS for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Basic shares 63,416 64,678 63,586 64,957 Dilutive shares 139 137 136 132 Diluted shares 63,555 64,815 63,722 65,089
Weighted-Average Antidilutive Stock Awards Excluded from Determining Diluted EPS	Weighted-average antidilutive stock awards were excluded in determining diluted EPS. The following table reflects weighted-average antidilutive stock awards for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Weighted-average antidilutive stock awards 11 23 63 78

Statements of Cash Flows (Table

Statements of Cash Flows (Tables)	6 Months Ended
	Jun. 30, 2020
Supplemental Cash Flow Information [Abstract]
Cash Flows Supplementary Disclosures	The following table reflects specific transaction amounts for the periods presented ($ in thousands): Six Months Ended June 30, 2020 2019 Income taxes paid $ 23,309 $ 5,336 Interest expense paid on deposits and borrowings 26,808 43,004 Noncash transfers from loans to other real estate 406 2,101 Finance right-of-use assets resulting from lease liabilities — 10,698 Operating right-of-use assets resulting from lease liabilities 671 32,762

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2020
Stockholders Equity Note [Abstract]
Table of Actual Regulatory Capital Amounts and Ratios	The following table provides Trustmark’s and TNB’s actual regulatory capital amounts and ratios under regulatory capital standards in effect at June 30, 2020 and December 31, 2019 ($ in thousands): Actual Regulatory Capital Minimum To Be Well Amount Ratio Requirement Capitalized At June 30, 2020: Common Equity Tier 1 Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,317,378 11.42 % 7.00 % n/a Trustmark National Bank 1,353,727 11.73 % 7.00 % 6.50 % Tier 1 Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,377,378 11.94 % 8.50 % n/a Trustmark National Bank 1,353,727 11.73 % 8.50 % 8.00 % Total Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,499,887 13.00 % 10.50 % n/a Trustmark National Bank 1,476,236 12.80 % 10.50 % 10.00 % Tier 1 Leverage (to Average Assets) Trustmark Corporation $ 1,377,378 9.08 % 4.00 % n/a Trustmark National Bank 1,353,727 8.94 % 4.00 % 5.00 % At December 31, 2019: Common Equity Tier 1 Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,312,668 11.93 % 7.00 % n/a Trustmark National Bank 1,352,893 12.30 % 7.00 % 6.50 % Tier 1 Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,372,668 12.48 % 8.50 % n/a Trustmark National Bank 1,352,893 12.30 % 8.50 % 8.00 % Total Capital (to Risk Weighted Assets) Trustmark Corporation $ 1,457,760 13.25 % 10.50 % n/a Trustmark National Bank 1,437,985 13.07 % 10.50 % 10.00 % Tier 1 Leverage (to Average Assets) Trustmark Corporation $ 1,372,668 10.48 % 4.00 % n/a Trustmark National Bank 1,352,893 10.35 % 4.00 % 5.00 %
Net Change in Components of Accumulated Other Comprehensive Income (Loss) and the Related Tax Effects	Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Before Tax Amount Tax (Expense) Benefit Net of Tax Amount Before Tax Amount Tax (Expense) Benefit Net of Tax Amount Securities available for sale and transferred securities: Net unrealized holding gains (losses) arising during the period $ 43,155 $ (10,789 ) $ 32,366 $ 38,903 $ (9,726 ) $ 29,177 Change in net unrealized holding loss on securities transferred to held to maturity 1,639 (410 ) 1,229 2,003 (501 ) 1,502 Total securities available for sale and transferred securities 44,794 (11,199 ) 33,595 40,906 (10,227 ) 30,679 Pension and other postretirement benefit plans: Reclassification adjustments for changes realized in net income: Net change in prior service costs 75 (19 ) 56 125 (31 ) 94 Recognized net loss due to lump sum settlements 40 (10 ) 30 94 (23 ) 71 Change in net actuarial loss 645 (161 ) 484 502 (126 ) 376 Total pension and other postretirement benefit plans 760 (190 ) 570 721 (180 ) 541 Cash flow hedge derivatives: Change in accumulated gain (loss) on effective cash flow hedge derivatives — — — (164 ) 41 (123 ) Reclassification adjustment for (gain) loss realized in net income — — — (312 ) 78 (234 ) Total cash flow hedge derivatives — — — (476 ) 119 (357 ) Total other comprehensive income (loss) $ 45,554 $ (11,389 ) $ 34,165 $ 41,151 $ (10,288 ) $ 30,863
Components of Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	The following table presents the changes in the balances of each component of accumulated other comprehensive income (loss) for the periods presented ($ in thousands). All amounts are presented net of tax. Securities Available and Transferred Securities Defined Benefit Pension Items Cash Flow Hedge Derivatives Total Balance at January 1, 2020 $ (8,017 ) $ (15,583 ) $ — $ (23,600 ) Other comprehensive income (loss) before reclassification 33,595 — — 33,595 Amounts reclassified from accumulated other comprehensive income (loss) — 570 — 570 Net other comprehensive income (loss) 33,595 570 — 34,165 Balance at June 30, 2020 $ 25,578 $ (15,013 ) $ — $ 10,565 Balance at January 1, 2019 $ (43,824 ) $ (12,324 ) $ 469 $ (55,679 ) Other comprehensive income (loss) before reclassification 30,679 — (123 ) 30,556 Amounts reclassified from accumulated other comprehensive income (loss) — 541 (234 ) 307 Net other comprehensive income (loss) 30,679 541 (357 ) 30,863 Balance at June 30, 2019 $ (13,145 ) $ (11,783 ) $ 112 $ (24,816 )

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value Recurring Basis	The following tables summarize financial assets and financial liabilities measured at fair value on a recurring basis as of June 30, 2020 and December 31, 2019, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value ($ in thousands). There were no transfers between fair value levels for the six months ended June 30, 2020 and the year ended December 31, 2019. June 30, 2020 Total Level 1 Level 2 Level 3 U.S. Government agency obligations $ 19,898 $ — $ 19,898 $ — Obligations of states and political subdivisions 11,176 — 11,176 — Mortgage-backed securities 1,853,079 — 1,853,079 — Securities available for sale 1,884,153 — 1,884,153 — Loans held for sale 355,089 — 355,089 — Mortgage servicing rights 57,811 — — 57,811 Other assets - derivatives 58,880 843 43,707 14,330 Other liabilities - derivatives 4,994 335 4,659 — December 31, 2019 Total Level 1 Level 2 Level 3 U.S. Government agency obligations $ 22,327 $ — $ 22,327 $ — Obligations of states and political subdivisions 25,465 — 25,465 — Mortgage-backed securities 1,554,612 — 1,554,612 — Securities available for sale 1,602,404 — 1,602,404 — Loans held for sale 226,347 — 226,347 — Mortgage servicing rights 79,394 — — 79,394 Other assets - derivatives 17,956 244 16,273 1,439 Other liabilities - derivatives 6,063 4,414 1,649 —
Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis	The changes in Level 3 assets measured at fair value on a recurring basis for the six months ended June 30, 2020 and 2019 are summarized as follows ($ in thousands): MSR Other Assets - Derivatives Balance, January 1, 2020 $ 79,394 $ 1,439 Total net (loss) gain included in Mortgage banking, net (1) (33,979 ) 22,382 Additions 12,396 — Sales — (9,491 ) Balance, June 30, 2020 $ 57,811 $ 14,330 The amount of total gains (losses) for the period included in earnings that are attributable to the change in unrealized gains or losses still held at June 30, 2020 $ (27,158 ) $ 12,897 Balance, January 1, 2019 $ 95,596 $ 1,187 Total net (loss) gain included in Mortgage banking, net (1) (22,388 ) 3,889 Additions 6,075 — Sales — (2,531 ) Balance, June 30, 2019 $ 79,283 $ 2,545 The amount of total gains (losses) for the period included in earnings that are attributable to the change in unrealized gains or losses still held at June 30, 2019 $ (17,072 ) $ 678 (1) Total net (loss) gain included in Mortgage banking, net relating to the MSR includes changes in fair value due to market changes and due to run-off.
Carrying Amounts and Estimated Fair Values of Financial Instruments	The carrying amounts and estimated fair values of financial instruments at June 30, 2020 and December 31, 2019, are as follows ($ in thousands): June 30, 2020 December 31, 2019 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Financial Assets: Level 2 Inputs: Cash and short-term investments $ 1,026,640 $ 1,026,640 $ 358,916 $ 358,916 Securities held to maturity 660,048 690,561 738,099 746,202 Level 3 Inputs: Net LHFI and PPP loans 10,480,401 10,500,218 9,251,351 9,235,674 Net acquired loans (1) — — 71,786 71,786 Financial Liabilities: Level 2 Inputs: Deposits 13,505,473 13,512,248 11,245,557 11,250,071 Federal funds purchased and securities sold under repurchase agreements 70,255 70,255 256,020 256,020 Other borrowings 152,860 152,861 85,396 85,374 Junior subordinated debt securities 61,856 45,155 61,856 50,722 (1) Upon adoption of FASB ASC Topic 326 at January 1, 2020, Trustmark elected to account for its existing acquired loans as purchased credit deteriorated loans included within the LHFI portfolio. See Note 4 – Acquired Loans for additional details.
Fair Value and the Contractual Principal Outstanding of the LHFS	The following table provides information about the fair value and the contractual principal outstanding of LHFS accounted for under the fair value option as of June 30, 2020 and December 31, 2019 ($ in thousands): June 30, 2020 December 31, 2019 Fair value of LHFS $ 233,687 $ 169,285 LHFS contractual principal outstanding 221,365 164,420 Fair value less unpaid principal $ 12,322 $ 4,865

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments	The following tables disclose the fair value of derivative instruments in Trustmark’s consolidated balance sheets as of June 30, 2020 and December 31, 2019 as well as the effect of these derivative instruments on Trustmark’s results of operations for the periods presented ($ in thousands): June 30, 2020 December 31, 2019 Derivatives not designated as hedging instruments Interest rate contracts: Futures contracts included in other assets $ 509 $ — Exchange traded purchased options included in other assets 334 244 OTC written options (rate locks) included in other assets 14,330 1,439 Interest rate swaps included in other assets 43,579 16,209 Credit risk participation agreements included in other assets 128 64 Futures contracts included in other liabilities — 2,654 Forward contracts included in other liabilities 2,574 486 Exchange traded written options included in other liabilities 335 1,760 Interest rate swaps included in other liabilities 1,932 1,122 Credit risk participation agreements included in other liabilities 153 41
Effects of Derivative Instruments on Statements of Operations	Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Derivatives in hedging relationships Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) and recognized in other interest expense $ — $ 141 $ — $ 312 Derivatives not designated as hedging instruments Amount of gain (loss) recognized in mortgage banking, net $ 12,395 $ 7,944 $ 45,881 $ 12,797 Amount of gain (loss) recognized in bank card and other fees (76 ) (487 ) (1,736 ) (743 )
Schedule of Amount Included in Other Comprehensive Income for Derivative Instruments Designated as Hedges of Cash Flows	The following table discloses the amount included in other comprehensive income (loss), net of tax, for derivative instruments designated as cash flow hedges for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Derivatives in cash flow hedging relationship Amount of gain (loss) recognized in other comprehensive income (loss), net of tax $ — $ (76 ) $ — $ (123 )
Information about Financial Instruments that are Eligible for Offset in the Consolidated Balance Sheets	Information about financial instruments that are eligible for offset in the consolidated balance sheets as of June 30, 2020 and December 31, 2019 is presented in the following tables ($ in thousands): Offsetting of Derivative Assets As of June 30, 2020 Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets presented in the Statement of Financial Position Financial Instruments Cash Collateral Received Net Amount Derivatives $ 43,579 $ — $ 43,579 $ (1 ) $ — $ 43,578 Offsetting of Derivative Liabilities As of June 30, 2020 Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Position Net Amounts of Liabilities presented in the Statement of Financial Position Financial Instruments Cash Collateral Posted Net Amount Derivatives $ 1,932 $ — $ 1,932 $ (1 ) $ (1,931 ) $ — Offsetting of Derivative Assets As of December 31, 2019 Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets presented in the Statement of Financial Position Financial Instruments Cash Collateral Received Net Amount Derivatives $ 16,209 $ — $ 16,209 $ — $ — $ 16,209 Offsetting of Derivative Liabilities As of December 31, 2019 Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Position Net Amounts of Liabilities presented in the Statement of Financial Position Financial Instruments Cash Collateral Posted Net Amount Derivatives $ 1,122 $ — $ 1,122 $ — $ (1,390 ) $ (268 )

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Schedule of Segment Information	The following table discloses financial information by reportable segment for the periods presented ($ in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 General Banking Net interest income $ 103,376 $ 105,897 $ 205,779 $ 208,902 Provision for credit losses 18,188 2,596 36,562 4,289 Noninterest income 50,051 30,808 95,227 53,721 Noninterest expense 103,355 90,093 209,805 180,108 Income before income taxes 31,884 44,016 54,639 78,226 Income taxes 4,093 5,362 6,184 9,517 General banking net income $ 27,791 $ 38,654 $ 48,455 $ 68,709 Selected Financial Information Total assets $ 15,378,653 $ 13,161,680 $ 15,378,653 $ 13,161,680 Depreciation and amortization $ 10,422 $ 9,592 $ 19,216 $ 18,731 Wealth Management Net interest income $ 1,576 $ 1,772 $ 3,080 $ 3,520 Provision for credit losses (3 ) (4 ) 2,204 (8 ) Noninterest income 7,550 7,740 16,066 15,443 Noninterest expense 6,944 7,727 15,460 15,390 Income before income taxes 2,185 1,789 1,482 3,581 Income taxes 547 447 371 891 Wealth management net income $ 1,638 $ 1,342 $ 1,111 $ 2,690 Selected Financial Information Total assets $ 232,467 $ 313,398 $ 232,467 $ 313,398 Depreciation and amortization $ 67 $ 68 $ 134 $ 137 Insurance Net interest income $ 48 $ 55 $ 93 $ 110 Noninterest income 11,910 11,091 23,482 21,966 Noninterest expense 8,360 8,281 17,204 16,624 Income before income taxes 3,598 2,865 6,371 5,452 Income taxes 877 721 1,569 1,372 Insurance net income $ 2,721 $ 2,144 $ 4,802 $ 4,080 Selected Financial Information Total assets $ 80,959 $ 73,880 $ 80,959 $ 73,880 Depreciation and amortization $ 171 $ 126 $ 306 $ 255 Consolidated Net interest income $ 105,000 $ 107,724 $ 208,952 $ 212,532 Provision for credit losses 18,185 2,592 38,766 4,281 Noninterest income 69,511 49,639 134,775 91,130 Noninterest expense 118,659 106,101 242,469 212,122 Income before income taxes 37,667 48,670 62,492 87,259 Income taxes 5,517 6,530 8,124 11,780 Consolidated net income $ 32,150 $ 42,140 $ 54,368 $ 75,479 Selected Financial Information Total assets $ 15,692,079 $ 13,548,958 $ 15,692,079 $ 13,548,958 Depreciation and amortization $ 10,660 $ 9,786 $ 19,656 $ 19,123

Business, Basis of Financial _2

Business, Basis of Financial Statement Presentation and Principles of Consolidation (Details) $ in Thousands	Jun. 05, 2020	Mar. 27, 2020USD ($)	Jun. 30, 2020USD ($)OfficeLoan
Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items]
Number of offices | Office			187
Financing receivable, loans outstanding | Loan			9,693
Financing receivable, loan amount			$ 939,783
Financing receivable, deferred fees and costs			$ 29,900
Small Business Administration (SBA), CARES Act, Paycheck Protection Program [Member]
Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items]
Provision for CARES Act		$ 349,000,000
Financing Receivable, interest rate		1.00%
Financing Receivable, loan term		2 years
Small Business Administration (SBA), CARES Act, Paycheck Protection Program [Member] | Minimum [Member]
Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items]
Financing Receivable, loan term	5 years
Financing receivable, existing loans maturity term	5 years
Financing Receivable, processing fee percentage	1.00%
Small Business Administration (SBA), CARES Act, Paycheck Protection Program [Member] | Maximum [Member]
Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items]
Financing receivable, existing loans maturity term	10 years
Financing receivable, guaranteed percentage	100.00%
Financing Receivable, processing fee percentage	5.00%

Securities Available for Sale_3

Securities Available for Sale and Held to Maturity - Additional Information (Details) - USD ($)	Jan. 01, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2013
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities held to maturity		$ 660,048,000		$ 738,099,000
Potential credit loss exposure		31,500,000
Reclassification of Securities available for sale to securities held to maturity					$ 1,099,000,000
Net unrealized holding loss on AFS Securities at date of transfer					46,600,000
Net unrealized holding losses on AFS Securities, net of tax at date of transfer					$ 28,800,000
Net unamortized, unrealized loss on transfer of securities		10,500,000		12,100,000
Net unamortized, unrealized loss on transfer of securities, net of tax		7,900,000		9,100,000
Other-than-temporary impairments			$ 0
Pledged to collateralize public deposits and securities sold under repurchase agreements and for other purposes as permitted by law		1,974,000,000		1,770,000,000
Pledged securities providing additional contingency funding		0		$ 0
30 Days or More Past Due [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Held-to-maturity, past due		0
Securities Available for Sale [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Accrued interest receivable		4,200,000
Securities Held to Maturity [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Accrued interest receivable		1,400,000
Reserve for credit loss		0
Held-to-maturity nonnaccrual		0
ASU 2016-13 [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Cumulative effect adjustment through retained earnings	$ 19,900,000
Securities held to maturity		660,000,000
ASU 2016-13 [Member] | Securities Available for Sale [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Expected credit loss		0
Cumulative effect adjustment through retained earnings	0
ASU 2016-13 [Member] | Securities Held to Maturity [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Cumulative effect adjustment through retained earnings	$ 0
Current expected credit loss		$ 0

Securities Available for Sale_4

Securities Available for Sale and Held to Maturity - Securities Held to Maturity by Credit Rating, as Determined by Moody's (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Held to Maturity Amortized Cost	$ 660,048	$ 738,099
Aaa [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Held to Maturity Amortized Cost	628,419
Aaa1 to Aa3 [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Held to Maturity Amortized Cost	26,179
Not Rated [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Held to Maturity Amortized Cost	$ 5,450

Securities Available for Sale_5

Securities Available for Sale and Held to Maturity - Amortized Cost and Estimated Fair Value of Available for Sale and Held to Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	$ 1,839,578	$ 1,600,984
Securities Available for Sale, Gross Unrealized Gains	45,136	7,580
Securities Available for Sale, Gross Unrealized (Losses)	(561)	(6,160)
Securities Available for Sale, Estimated Fair Value	1,884,153	1,602,404
Securities Held to Maturity, Amortized Cost	660,048	738,099
Securities Held to Maturity, Gross Unrealized Gains	30,538	9,274
Securities Held to Maturity, Gross Unrealized (Losses)	(25)	(1,171)
Securities Held to Maturity, Estimated Fair Value	690,561	746,202
U.S. Government Agency Obligations [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	20,254	22,965
Securities Available for Sale, Gross Unrealized Gains	160	69
Securities Available for Sale, Gross Unrealized (Losses)	(516)	(707)
Securities Available for Sale, Estimated Fair Value	19,898	22,327
Securities Held to Maturity, Amortized Cost	0	3,781
Securities Held to Maturity, Gross Unrealized Gains	0	220
Securities Held to Maturity, Gross Unrealized (Losses)	0	0
Securities Held to Maturity, Estimated Fair Value	0	4,001
Obligations of States and Political Subdivisions [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	10,565	24,952
Securities Available for Sale, Gross Unrealized Gains	611	513
Securities Available for Sale, Gross Unrealized (Losses)	0	0
Securities Available for Sale, Estimated Fair Value	11,176	25,465
Securities Held to Maturity, Amortized Cost	31,629	31,781
Securities Held to Maturity, Gross Unrealized Gains	461	434
Securities Held to Maturity, Gross Unrealized (Losses)	(25)	(53)
Securities Held to Maturity, Estimated Fair Value	32,065	32,162
Residential Mortgage Pass-Through Securities Guaranteed by GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	67,439	69,196
Securities Available for Sale, Gross Unrealized Gains	2,199	425
Securities Available for Sale, Gross Unrealized (Losses)	(1)	(369)
Securities Available for Sale, Estimated Fair Value	69,637	69,252
Securities Held to Maturity, Amortized Cost	10,306	10,820
Securities Held to Maturity, Gross Unrealized Gains	548	266
Securities Held to Maturity, Gross Unrealized (Losses)	0	(10)
Securities Held to Maturity, Estimated Fair Value	10,854	11,076
Residential Mortgage Pass-Through Securities Issued by FNMA and FHLMC [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	1,096,861	714,350
Securities Available for Sale, Gross Unrealized Gains	24,762	2,171
Securities Available for Sale, Gross Unrealized (Losses)	(19)	(3,165)
Securities Available for Sale, Estimated Fair Value	1,121,604	713,356
Securities Held to Maturity, Amortized Cost	86,346	96,631
Securities Held to Maturity, Gross Unrealized Gains	3,204	286
Securities Held to Maturity, Gross Unrealized (Losses)	0	(370)
Securities Held to Maturity, Estimated Fair Value	89,550	96,547
Other Residential Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	560,109	656,162
Securities Available for Sale, Gross Unrealized Gains	14,846	3,777
Securities Available for Sale, Gross Unrealized (Losses)	(15)	(1,713)
Securities Available for Sale, Estimated Fair Value	574,940	658,226
Securities Held to Maturity, Amortized Cost	435,333	485,324
Securities Held to Maturity, Gross Unrealized Gains	23,148	7,026
Securities Held to Maturity, Gross Unrealized (Losses)	0	(656)
Securities Held to Maturity, Estimated Fair Value	458,481	491,694
Commercial Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	84,350	113,359
Securities Available for Sale, Gross Unrealized Gains	2,558	625
Securities Available for Sale, Gross Unrealized (Losses)	(10)	(206)
Securities Available for Sale, Estimated Fair Value	86,898	113,778
Securities Held to Maturity, Amortized Cost	96,434	109,762
Securities Held to Maturity, Gross Unrealized Gains	3,177	1,042
Securities Held to Maturity, Gross Unrealized (Losses)	0	(82)
Securities Held to Maturity, Estimated Fair Value	$ 99,611	$ 110,722

Securities Available for Sale_6

Securities Available for Sale and Held to Maturity - Securities with Gross Unrealized Losses, Segregated by Length of Impairment (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	$ 23,405	$ 352,661
Estimated Fair Value, 12 Months or More	27,467	481,177
Estimated Fair Value, Total	50,872	833,838
Gross Unrealized (Losses), Less than 12 Months	(23)	(1,347)
Gross Unrealized (Losses), 12 Months or More	(563)	(5,984)
Gross Unrealized (Losses), Total	(586)	(7,331)
U.S. Government Agency Obligations [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	0	6,585
Estimated Fair Value, 12 Months or More	11,624	12,886
Estimated Fair Value, Total	11,624	19,471
Gross Unrealized (Losses), Less than 12 Months	0	(105)
Gross Unrealized (Losses), 12 Months or More	(516)	(602)
Gross Unrealized (Losses), Total	(516)	(707)
Obligations of States and Political Subdivisions [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	0	0
Estimated Fair Value, 12 Months or More	6,221	6,216
Estimated Fair Value, Total	6,221	6,216
Gross Unrealized (Losses), Less than 12 Months	0	0
Gross Unrealized (Losses), 12 Months or More	(25)	(53)
Gross Unrealized (Losses), Total	(25)	(53)
Residential Mortgage Pass-Through Securities Guaranteed by GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	325	23,544
Estimated Fair Value, 12 Months or More	0	18,529
Estimated Fair Value, Total	325	42,073
Gross Unrealized (Losses), Less than 12 Months	(1)	(107)
Gross Unrealized (Losses), 12 Months or More	0	(272)
Gross Unrealized (Losses), Total	(1)	(379)
Residential Mortgage Pass-Through Securities Issued by FNMA and FHLMC [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	20,644	112,879
Estimated Fair Value, 12 Months or More	8,954	278,120
Estimated Fair Value, Total	29,598	390,999
Gross Unrealized (Losses), Less than 12 Months	(7)	(230)
Gross Unrealized (Losses), 12 Months or More	(12)	(3,305)
Gross Unrealized (Losses), Total	(19)	(3,535)
Other Residential Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	2,436	158,341
Estimated Fair Value, 12 Months or More	0	151,271
Estimated Fair Value, Total	2,436	309,612
Gross Unrealized (Losses), Less than 12 Months	(15)	(738)
Gross Unrealized (Losses), 12 Months or More	0	(1,631)
Gross Unrealized (Losses), Total	(15)	(2,369)
Commercial Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	0	51,312
Estimated Fair Value, 12 Months or More	668	14,155
Estimated Fair Value, Total	668	65,467
Gross Unrealized (Losses), Less than 12 Months	0	(167)
Gross Unrealized (Losses), 12 Months or More	(10)	(121)
Gross Unrealized (Losses), Total	$ (10)	$ (288)

Securities Available for Sale_7

Securities Available for Sale and Held to Maturity - Contractual Maturities of Available for Sale and Held to Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Securities Available for Sale, Amortized Cost [Abstract]
Due in one year or less	$ 7,867
Due after one year through five years	1,559
Due after five years through ten years	2,161
Due after ten years	19,232
Total amortized cost, before mortgage-backed securities	30,819
Mortgage-backed securities	1,808,759
Securities Available for Sale, Amortized Cost	1,839,578	$ 1,600,984
Securities Available for Sale, Estimated Fair Value [Abstract]
Due in one year or less	7,945
Due after one year through five years	1,601
Due after five years through ten years	2,112
Due after ten years	19,416
Total fair value, before mortgage-backed securities	31,074
Mortgage-backed securities	1,853,079
Total	1,884,153	1,602,404
Securities Held to Maturity, Amortized Cost [Abstract]
Due in one year or less	18,599
Due after one year through five years	13,030
Due after five years through ten years	0
Due after ten years	0
Total amortized cost, before mortgage-backed securities	31,629
Mortgage-backed securities	628,419
Securities Held to Maturity, Amortized Cost	660,048	738,099
Securities Held to Maturity, Estimated Fair Value [Abstract]
Due in one year or less	18,715
Due after one year through five years	13,350
Due after five years through ten years	0
Due after ten years	0
Total fair value, before mortgage-backed securities	32,065
Mortgage-backed securities	658,496
Total	$ 690,561	$ 746,202

Loans Held for Investment (LH_3

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Loan Portfolio Held for Investment (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Loan Portfolio [Abstract]
Total LHFI	[1]	$ 9,659,806	$ 9,335,628
Less allowance for credit losses (ACL), LHFI	[1]	119,188	84,277
Net LHFI		9,540,618	9,251,351
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI		482,309	1,162,791
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	[2]	1,250,697
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI		562,828	1,855,913
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI		884,815	724,480
Other Construction [Member] | Other Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	[2]	794,968
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI		2,610,392	2,475,245
Commercial and Industrial Loans [Member]
Loan Portfolio [Abstract]
Total LHFI		1,413,255	1,477,896
Consumer Loans [Member]
Loan Portfolio [Abstract]
Total LHFI		164,560	175,738
State and Other Political Subdivision Loans [Member]
Loan Portfolio [Abstract]
Total LHFI		931,536	967,944
Other Commercial Loans [Member]
Loan Portfolio [Abstract]
Total LHFI	[2]	$ 564,446	$ 495,621
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.
[2]	In accordance with the guidance in FASB ASC Topic 326, Trustmark redefined its LHFI portfolio segments and related loan classes based on the level at which risk is monitored within the ACL methodology. The other loans secured by real estate portfolio segment and related loan classes were separated from the loans secured by real estate portfolio segment. The other construction loans were segregated from the construction, land development and other land loans. The other loans secured by 1-4 family residential properties were segregated from the loans secured by 1-4 family residential properties and the loans secured by 1-4 family residential properties were redefined in the other loans secured by real estate portfolio segment. Other loans were redefined as other commercial loans.

Loans Held for Investment (LH_4

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Additional Information (Details 1)	6 Months Ended
	Jun. 30, 2020USD ($)LoanRegion	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Financing Receivable Impaired [Line Items]
Accrued interest receivable	$ 35,600
Maximum concentration of loan as a percentage of total LHFI	10.00%
Key market regions | Region	5
Number of days to pass to be classified as past due LHFI	30 days
Minimum loan amount for loan to be specifically reviewed for impairment and deemed impaired			$ 500,000
LHFI classified as TDRs	$ 26,900,000	$ 36,300,000
LHFI classified as TDRs from credits with interest only payments	14,600,000	25,700,000
Unused commitments on TDRs	5,600,000	2,300,000
Financing receivable, related allowance	2,000,000	2,900,000
Financing receivable, related charge-offs	$ 2,200,000	$ 117,000
Number of individual loans modified as per CARES Act | Loan	2,692
Aggregate principal balances of loans modified as per CARES Act	$ 1,422,000,000
Period of extension on interest part of loans modified as per CARES Act	90 days
Period of extension on full payment deferrals part of loans modified as per CARES Act	90 days
Commercial Credits [Member]
Financing Receivable Impaired [Line Items]
Number of days past due for loan to be classified as nonaccrual	90 days
Non-Business Purpose Credits [Member]
Financing Receivable Impaired [Line Items]
Number of days past due for loan to be classified as nonaccrual	120 days

Loans Held for Investment (LH_5

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Schedule of Amortized Cost Basis of Loans on Nonaccrual Status (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual With No ACL	$ 24,451
Total Nonaccrual	49,994	$ 53,226
Loans Past Due 90 Days or More Still Accruing	807
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual With No ACL	575
Total Nonaccrual	932	897
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual With No ACL	496
Total Nonaccrual	4,441
Loans Past Due 90 Days or More Still Accruing	51
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual With No ACL	5,389
Total Nonaccrual	7,883	7,700
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual With No ACL	63
Total Nonaccrual	881	1,032
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Nonaccrual		16,810
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual With No ACL	1,480
Total Nonaccrual	12,523
Loans Past Due 90 Days or More Still Accruing	528
Commercial and Industrial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual With No ACL	16,436
Total Nonaccrual	18,181	21,775
Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Nonaccrual	120	108
Loans Past Due 90 Days or More Still Accruing	217
State and Other Political Subdivision Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Nonaccrual	4,049	$ 4,079
Other Commercial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual With No ACL	12
Total Nonaccrual	984
Loans Past Due 90 Days or More Still Accruing	$ 11

Loans Held for Investment (LH_6

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Aging Analysis of Past Due and Nonaccrual LHFI by Loan Type (Details) - USD ($) $ in Thousands		Jun. 30, 2020		Dec. 31, 2019
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		$ 19,869		$ 12,627
Nonaccrual		49,994		53,226
Current Loans		9,639,937		9,269,775
Total LHFI	[1]	9,659,806		9,335,628
Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		6,236		10,393
Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		3,498	[2]	1,592
Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		10,135		642	[2]
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		1,213		636
Nonaccrual		932		897
Current Loans		481,096		1,161,258
Total LHFI		482,309		1,162,791
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		699		380
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		323	[2]	256
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		191
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		3,130
Nonaccrual		4,441
Current Loans		559,698
Total LHFI		562,828
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		1,481
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due	[2]	1,017
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		632
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due				6,405
Nonaccrual				16,810
Current Loans				1,832,698
Total LHFI				1,855,913
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due				5,254
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due				940
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due	[2]			211
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		8,881
Nonaccrual		12,523
Current Loans		1,241,816
Total LHFI		1,250,697
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		1,880
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due	[2]	1,500
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		5,501
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		1,260		1,698
Nonaccrual		7,883		7,700
Current Loans		2,609,132		2,465,847
Total LHFI		2,610,392		2,475,245
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		187		1,698
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due	[2]	391
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		682
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		453		8
Nonaccrual		881		1,032
Current Loans		884,362		723,440
Total LHFI		884,815		724,480
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		165		8
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		288
Commercial and Industrial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		2,694		668
Nonaccrual		18,181		21,775
Current Loans		1,410,561		1,455,453
Total LHFI		1,413,255		1,477,896
Commercial and Industrial Loans [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		594		617
Commercial and Industrial Loans [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		99	[2]	12
Commercial and Industrial Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		2,001		39	[2]
Other Construction [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current Loans		794,968
Total LHFI		794,968
Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		1,248		2,980
Nonaccrual		120		108
Current Loans		163,312		172,650
Total LHFI		164,560		175,738
Consumer Loans [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		879		2,208
Consumer Loans [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		152	[2]	380
Consumer Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		217		392	[2]
State and Other Political Subdivision Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		177		76
Nonaccrual		4,049		4,079
Current Loans		931,359		963,789
Total LHFI		931,536		967,944
State and Other Political Subdivision Loans [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due				76
State and Other Political Subdivision Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		177
Other Commercial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		813
Nonaccrual		984
Current Loans		563,633
Total LHFI	[3]	564,446		495,621
Other Commercial Loans [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		351
Other Commercial Loans [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due	[2]	16
Other Commercial Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due		$ 446
Other Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due				156
Nonaccrual				825
Current Loans				494,640
Total LHFI				495,621
Other Loans [Member] | Past Due 30 to 59 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due				152
Other Loans [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Past Due				$ 4
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.
[2]	Past due 90 days or more but still accruing interest.
[3]	In accordance with the guidance in FASB ASC Topic 326, Trustmark redefined its LHFI portfolio segments and related loan classes based on the level at which risk is monitored within the ACL methodology. The other loans secured by real estate portfolio segment and related loan classes were separated from the loans secured by real estate portfolio segment. The other construction loans were segregated from the construction, land development and other land loans. The other loans secured by 1-4 family residential properties were segregated from the loans secured by 1-4 family residential properties and the loans secured by 1-4 family residential properties were redefined in the other loans secured by real estate portfolio segment. Other loans were redefined as other commercial loans.

Loans Held for Investment (LH_7

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Impaired Financing Receivables (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	$ 47,289
Total LHFI With No Related Allowance Recorded	23,550
Total LHFI With an Allowance Recorded	17,667
Total LHFI Recorded Investment	41,217
Related Allowance	5,459
Average Recorded Investment	48,525
Commercial and Industrial Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	27,178
Total LHFI With No Related Allowance Recorded	19,374
Total LHFI With an Allowance Recorded	4,084
Total LHFI Recorded Investment	23,458
Related Allowance	707
Average Recorded Investment	27,088
Consumer Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	22
Total LHFI With No Related Allowance Recorded	0
Total LHFI With an Allowance Recorded	21
Total LHFI Recorded Investment	21
Related Allowance	0
Average Recorded Investment	11
State and Other Political Subdivision Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	4,079
Total LHFI With No Related Allowance Recorded	0
Total LHFI With an Allowance Recorded	4,079
Total LHFI Recorded Investment	4,079
Related Allowance	1,809
Average Recorded Investment	6,337
Other Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	1,207
Total LHFI With No Related Allowance Recorded	0
Total LHFI With an Allowance Recorded	784
Total LHFI Recorded Investment	784
Related Allowance	553
Average Recorded Investment	1,033
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	926
Total LHFI With No Related Allowance Recorded	610
Total LHFI With an Allowance Recorded	16
Total LHFI Recorded Investment	626
Related Allowance	0
Average Recorded Investment	1,089
Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	6,513
Total LHFI With No Related Allowance Recorded	2,104
Total LHFI With an Allowance Recorded	3,360
Total LHFI Recorded Investment	5,464
Related Allowance	35
Average Recorded Investment	4,713
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	7,295
Total LHFI With No Related Allowance Recorded	1,462
Total LHFI With an Allowance Recorded	5,255
Total LHFI Recorded Investment	6,717
Related Allowance	2,355
Average Recorded Investment	8,096
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	69
Total LHFI With No Related Allowance Recorded	0
Total LHFI With an Allowance Recorded	68
Total LHFI Recorded Investment	68
Related Allowance	0
Average Recorded Investment	$ 158

Loans Held for Investment (LH_8

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Impact of Modifications Classified as Troubled Debt Restructurings (Details) - Troubled Debt Restructurings [Member] $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)Contract	Jun. 30, 2019USD ($)Contract	Jun. 30, 2020USD ($)Contract	Jun. 30, 2019USD ($)Contract
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	8	8	19	18
Pre-Modification Outstanding Recorded Investment	$ 4,253	$ 5,961	$ 6,356	$ 15,131
Post-Modification Outstanding Recorded Investment	$ 4,227	$ 5,847	$ 6,330	$ 15,017
Other Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	3	5	8	7
Pre-Modification Outstanding Recorded Investment	$ 206	$ 793	$ 707	$ 879
Post-Modification Outstanding Recorded Investment	$ 210	$ 792	$ 711	$ 878
Secured by Nonfarm, Nonresidential Properties [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	1	1	1	1
Pre-Modification Outstanding Recorded Investment	$ 139	$ 5,055	$ 139	$ 5,055
Post-Modification Outstanding Recorded Investment	$ 139	$ 5,055	$ 139	$ 5,055
Commercial and Industrial Loans [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract		2	2	8
Pre-Modification Outstanding Recorded Investment		$ 113	$ 1,582	$ 9,167
Post-Modification Outstanding Recorded Investment			$ 1,582	$ 9,054
Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	2		6	2
Pre-Modification Outstanding Recorded Investment	$ 6		$ 26	$ 30
Post-Modification Outstanding Recorded Investment	$ 6		$ 26	$ 30
State and Other Political Subdivision Loans [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	2		2
Pre-Modification Outstanding Recorded Investment	$ 3,902		$ 3,902
Post-Modification Outstanding Recorded Investment	$ 3,872		$ 3,872

Loans Held for Investment (LH_9

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Troubled Debt Restructuring Subsequently Defaulted (Details) - Troubled Debt Restructurings [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)Contract	Jun. 30, 2019USD ($)Contract
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	5	12
Recorded Investment | $	$ 641	$ 8,030
Other Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	3	1
Recorded Investment | $	$ 420	$ 46
Secured by Nonfarm, Nonresidential Properties [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	1	0
Recorded Investment | $	$ 139	$ 0
Commercial and Industrial Loans [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	1	10
Recorded Investment | $	$ 82	$ 7,957
Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Number of Contracts | Contract	0	1
Recorded Investment | $	$ 0	$ 27

Loans Held for Investment (L_10

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Troubled Debt Restructuring Related to Loans Held for Investment, Excluding Covered Loans, by Loan Type (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Financing Receivable Modifications [Line Items]
Nonaccrual	$ 49,994	$ 53,226
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	932	897
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	4,441
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	7,883	7,700
Commercial and Industrial Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	18,181	21,775
Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	120	108
State and Other Political Subdivision Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	4,049	4,079
Other Commercial Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	984
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual		16,810
Other Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual		$ 825
Troubled Debt Restructurings [Member]
Financing Receivable Modifications [Line Items]
Accruing	1,589		$ 14,947
Nonaccrual	25,290		21,399
Total	26,879		36,346
Troubled Debt Restructurings [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	0		0
Nonaccrual	14		20
Total	14		20
Troubled Debt Restructurings [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	71
Nonaccrual	3,761
Total	3,832
Troubled Debt Restructurings [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	0		0
Nonaccrual	3,010		5,311
Total	3,010		5,311
Troubled Debt Restructurings [Member] | Commercial and Industrial Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	1,500		14,897
Nonaccrual	14,487		11,965
Total	15,987		26,862
Troubled Debt Restructurings [Member] | Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	18		0
Nonaccrual	21		30
Total	39		30
Troubled Debt Restructurings [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	0
Nonaccrual	3,872
Total	3,872
Troubled Debt Restructurings [Member] | Other Commercial Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	0
Nonaccrual	125
Total	$ 125
Troubled Debt Restructurings [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing			50
Nonaccrual			3,563
Total			3,613
Troubled Debt Restructurings [Member] | Other Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing			0
Nonaccrual			510
Total			$ 510

Loans Held for Investment (L_11

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Schedule of Amortized Cost Basis of Collateral-Dependent Loans by Class of Loans and Collateral Type (Details) $ in Thousands	Jun. 30, 2020USD ($)
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	$ 42,130
Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	20,730
Equipment and Machinery [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	840
Inventory and Receivables [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	8,460
Vehicles [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	186
Miscellaneous [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	11,914
Construction, Land Development and Other Land [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	1,948
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	1,948
Other Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	496
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	496
Secured by Nonfarm, Nonresidential Properties [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	11,966
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	11,966
Other Real Estate Secured [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	63
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	63
Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	1,480
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	1,480
Commercial and Industrial Loans [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	16,364
Commercial and Industrial Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	105
Commercial and Industrial Loans [Member] | Equipment and Machinery [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	840
Commercial and Industrial Loans [Member] | Inventory and Receivables [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	6,439
Commercial and Industrial Loans [Member] | Vehicles [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	186
Commercial and Industrial Loans [Member] | Miscellaneous [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	8,794
State and Other Political Subdivision Loans [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	4,049
State and Other Political Subdivision Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	4,049
Other Commercial Loans [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	5,764
Other Commercial Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	623
Other Commercial Loans [Member] | Inventory and Receivables [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	2,021
Other Commercial Loans [Member] | Miscellaneous [Member]
Financing Receivable Impaired [Line Items]
Collateral-Dependent Loans	$ 3,120

Loans Held for Investment (L_12

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Additional Information (Details 2)		3 Months Ended		6 Months Ended
		Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)KeyRatio	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Financing Receivable, Recorded Investment, Aging [Abstract]
Number of days used as baseline in evaluating collateral documentation exceptions for loan policy				90 days
Number of key quality ratios | KeyRatio				6
LHFS past due 90 days or more		$ 56,300,000		$ 56,300,000		$ 41,600,000
Percentage of outstanding principal to be repurchased under GNMA optional repurchase program				100.00%
Minimum exposure for commercial accruing substandard loans to be reviewed on an individual basis		1,000,000		$ 1,000,000
Financing Receivable [Abstract]
PCL	[1]	18,185,000	$ 2,486,000	38,766,000	$ 4,097,000
Allowance for Credit Losses, ACL [Member]
Financing Receivable [Abstract]
PCL		18,185,000	$ 2,486,000	38,766,000	$ 4,097,000
Commercial and Industrial Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable [Abstract]
PCL		(1,908,000)		(3,932,000)
State and Other Political Subdivision Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable [Abstract]
PCL		(27,000)		(1,270,000)
Other Commercial Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable [Abstract]
PCL		307,000		(843,000)
Minimum [Member]
Financing Receivable [Abstract]
Credit amount used as baseline in evaluating loan policy		$ 100,000		$ 100,000
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Loans Held for Investment (L_13

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Summary of Amortized Cost Basis of Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	$ 1,343,412
Term Loans by Origination Year, 2019	2,167,880
Term Loans by Origination Year, 2018	1,544,809
Term Loans by Origination Year, 2017	953,747
Term Loans by Origination Year, 2016	917,347
Term Loans by Origination Year, Prior to 2016	1,447,202
Financing Receivable, Revolving Loans	1,285,409
Financing Receivable, before Allowance for Credit Loss	9,659,806
Commercial LHFI [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	1,141,257
Term Loans by Origination Year, 2019	1,821,629
Term Loans by Origination Year, 2018	1,276,005
Term Loans by Origination Year, 2017	823,097
Term Loans by Origination Year, 2016	779,143
Term Loans by Origination Year, Prior to 2016	1,023,985
Financing Receivable, Revolving Loans	863,338
Financing Receivable, before Allowance for Credit Loss	7,728,454	$ 7,348,158
Commercial LHFI [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		7,178,617
Commercial LHFI [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		9,049
Commercial LHFI [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		159,163
Commercial LHFI [Member] | Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,329
Commercial LHFI [Member] | Commercial and Industrial Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	313,012
Term Loans by Origination Year, 2019	284,333
Term Loans by Origination Year, 2018	131,371
Term Loans by Origination Year, 2017	96,040
Term Loans by Origination Year, 2016	83,208
Term Loans by Origination Year, Prior to 2016	59,387
Financing Receivable, Revolving Loans	445,904
Financing Receivable, before Allowance for Credit Loss	1,413,255	1,477,896
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	301,484
Term Loans by Origination Year, 2019	281,419
Term Loans by Origination Year, 2018	115,890
Term Loans by Origination Year, 2017	95,696
Term Loans by Origination Year, 2016	82,537
Term Loans by Origination Year, Prior to 2016	56,802
Financing Receivable, Revolving Loans	434,958
Financing Receivable, before Allowance for Credit Loss	1,368,786	1,407,837
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	850
Financing Receivable, Revolving Loans	833
Financing Receivable, before Allowance for Credit Loss	1,683	909
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	10,630
Term Loans by Origination Year, 2019	2,512
Term Loans by Origination Year, 2018	15,481
Term Loans by Origination Year, 2017	344
Term Loans by Origination Year, 2016	628
Term Loans by Origination Year, Prior to 2016	2,581
Financing Receivable, Revolving Loans	10,089
Financing Receivable, before Allowance for Credit Loss	42,265	68,262
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	48
Term Loans by Origination Year, 2019	402
Term Loans by Origination Year, 2016	43
Term Loans by Origination Year, Prior to 2016	4
Financing Receivable, Revolving Loans	24
Financing Receivable, before Allowance for Credit Loss	521	888
Commercial LHFI [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	85,513
Term Loans by Origination Year, 2019	109,844
Term Loans by Origination Year, 2018	54,240
Term Loans by Origination Year, 2017	119,871
Term Loans by Origination Year, 2016	144,165
Term Loans by Origination Year, Prior to 2016	417,005
Financing Receivable, Revolving Loans	898
Financing Receivable, before Allowance for Credit Loss	931,536	967,944
Commercial LHFI [Member] | State and Other Political Subdivision Loans [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	85,513
Term Loans by Origination Year, 2019	109,844
Term Loans by Origination Year, 2018	54,240
Term Loans by Origination Year, 2017	119,532
Term Loans by Origination Year, 2016	144,165
Term Loans by Origination Year, Prior to 2016	408,276
Financing Receivable, Revolving Loans	898
Financing Receivable, before Allowance for Credit Loss	922,468	957,948
Commercial LHFI [Member] | State and Other Political Subdivision Loans [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, Prior to 2016	4,000
Financing Receivable, before Allowance for Credit Loss	4,000	4,650
Commercial LHFI [Member] | State and Other Political Subdivision Loans [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	339
Term Loans by Origination Year, Prior to 2016	4,729
Financing Receivable, before Allowance for Credit Loss	5,068	5,346
Commercial LHFI [Member] | Other Commercial Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	74,403
Term Loans by Origination Year, 2019	86,158
Term Loans by Origination Year, 2018	29,571
Term Loans by Origination Year, 2017	14,866
Term Loans by Origination Year, 2016	59,015
Term Loans by Origination Year, Prior to 2016	54,138
Financing Receivable, Revolving Loans	246,295
Financing Receivable, before Allowance for Credit Loss	564,446
Commercial LHFI [Member] | Other Commercial Loans [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	66,388
Term Loans by Origination Year, 2019	83,965
Term Loans by Origination Year, 2018	28,885
Term Loans by Origination Year, 2017	14,821
Term Loans by Origination Year, 2016	57,952
Term Loans by Origination Year, Prior to 2016	54,114
Financing Receivable, Revolving Loans	224,792
Financing Receivable, before Allowance for Credit Loss	530,917
Commercial LHFI [Member] | Other Commercial Loans [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	7,917
Financing Receivable, Revolving Loans	11,833
Financing Receivable, before Allowance for Credit Loss	19,750
Commercial LHFI [Member] | Other Commercial Loans [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	98
Term Loans by Origination Year, 2019	2,190
Term Loans by Origination Year, 2018	686
Term Loans by Origination Year, 2017	45
Term Loans by Origination Year, 2016	1,063
Term Loans by Origination Year, Prior to 2016	1
Financing Receivable, Revolving Loans	9,670
Financing Receivable, before Allowance for Credit Loss	13,753
Commercial LHFI [Member] | Other Commercial Loans [Member] | Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	3
Term Loans by Origination Year, Prior to 2016	23
Financing Receivable, before Allowance for Credit Loss	26
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	172,535
Term Loans by Origination Year, 2019	146,498
Term Loans by Origination Year, 2018	37,169
Term Loans by Origination Year, 2017	5,460
Term Loans by Origination Year, 2016	4,251
Term Loans by Origination Year, Prior to 2016	5,260
Financing Receivable, Revolving Loans	37,106
Financing Receivable, before Allowance for Credit Loss	408,279
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	170,118
Term Loans by Origination Year, 2019	146,424
Term Loans by Origination Year, 2018	36,674
Term Loans by Origination Year, 2017	5,413
Term Loans by Origination Year, 2016	3,571
Term Loans by Origination Year, Prior to 2016	5,192
Financing Receivable, Revolving Loans	37,106
Financing Receivable, before Allowance for Credit Loss	404,498
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	2,417
Term Loans by Origination Year, 2019	74
Term Loans by Origination Year, 2018	495
Term Loans by Origination Year, 2017	47
Term Loans by Origination Year, 2016	680
Term Loans by Origination Year, Prior to 2016	26
Financing Receivable, before Allowance for Credit Loss	3,739
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, Prior to 2016	42
Financing Receivable, before Allowance for Credit Loss	42
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	26,218
Term Loans by Origination Year, 2019	29,291
Term Loans by Origination Year, 2018	23,089
Term Loans by Origination Year, 2017	12,196
Term Loans by Origination Year, 2016	14,212
Term Loans by Origination Year, Prior to 2016	9,355
Financing Receivable, Revolving Loans	7,010
Financing Receivable, before Allowance for Credit Loss	121,371
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	21,491
Term Loans by Origination Year, 2019	28,901
Term Loans by Origination Year, 2018	22,057
Term Loans by Origination Year, 2017	11,956
Term Loans by Origination Year, 2016	14,141
Term Loans by Origination Year, Prior to 2016	8,565
Financing Receivable, Revolving Loans	7,010
Financing Receivable, before Allowance for Credit Loss	114,121
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	90
Financing Receivable, before Allowance for Credit Loss	90
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	4,694
Term Loans by Origination Year, 2019	299
Term Loans by Origination Year, 2018	1,032
Term Loans by Origination Year, 2017	240
Term Loans by Origination Year, 2016	71
Term Loans by Origination Year, Prior to 2016	790
Financing Receivable, before Allowance for Credit Loss	7,126
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	33
Term Loans by Origination Year, 2019	1
Financing Receivable, before Allowance for Credit Loss	34
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	68,617
Term Loans by Origination Year, 2019	181,430
Term Loans by Origination Year, 2018	295,694
Term Loans by Origination Year, 2017	160,526
Term Loans by Origination Year, 2016	130,873
Term Loans by Origination Year, Prior to 2016	36,772
Financing Receivable, Revolving Loans	10,314
Financing Receivable, before Allowance for Credit Loss	884,226
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	67,416
Term Loans by Origination Year, 2019	181,243
Term Loans by Origination Year, 2018	295,676
Term Loans by Origination Year, 2017	160,526
Term Loans by Origination Year, 2016	130,810
Term Loans by Origination Year, Prior to 2016	35,183
Financing Receivable, Revolving Loans	10,314
Financing Receivable, before Allowance for Credit Loss	881,168
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, Prior to 2016	874
Financing Receivable, before Allowance for Credit Loss	874
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	1,201
Term Loans by Origination Year, 2019	187
Term Loans by Origination Year, 2018	18
Term Loans by Origination Year, 2016	63
Term Loans by Origination Year, Prior to 2016	715
Financing Receivable, before Allowance for Credit Loss	2,184
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	324,216
Term Loans by Origination Year, 2019	536,071
Term Loans by Origination Year, 2018	468,946
Term Loans by Origination Year, 2017	388,181
Term Loans by Origination Year, 2016	341,938
Term Loans by Origination Year, Prior to 2016	442,068
Financing Receivable, Revolving Loans	108,953
Financing Receivable, before Allowance for Credit Loss	2,610,373	2,475,090
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	315,293
Term Loans by Origination Year, 2019	519,415
Term Loans by Origination Year, 2018	466,036
Term Loans by Origination Year, 2017	384,595
Term Loans by Origination Year, 2016	332,457
Term Loans by Origination Year, Prior to 2016	424,260
Financing Receivable, Revolving Loans	108,032
Financing Receivable, before Allowance for Credit Loss	2,550,088	2,430,761
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	5,655
Term Loans by Origination Year, 2018	1,083
Term Loans by Origination Year, 2016	350
Term Loans by Origination Year, Prior to 2016	4,894
Financing Receivable, before Allowance for Credit Loss	11,982
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	8,866
Term Loans by Origination Year, 2019	10,821
Term Loans by Origination Year, 2018	1,827
Term Loans by Origination Year, 2017	3,586
Term Loans by Origination Year, 2016	9,131
Term Loans by Origination Year, Prior to 2016	12,583
Financing Receivable, Revolving Loans	921
Financing Receivable, before Allowance for Credit Loss	47,735	44,001
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	57
Term Loans by Origination Year, 2019	180
Term Loans by Origination Year, Prior to 2016	331
Financing Receivable, before Allowance for Credit Loss	568	328
Commercial LHFI [Member] | Other Loans Secured by Real Estate [Member] | Other Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	76,743
Term Loans by Origination Year, 2019	448,004
Term Loans by Origination Year, 2018	235,925
Term Loans by Origination Year, 2017	25,957
Term Loans by Origination Year, 2016	1,481
Financing Receivable, Revolving Loans	6,858
Financing Receivable, before Allowance for Credit Loss	794,968
Commercial LHFI [Member] | Other Loans Secured by Real Estate [Member] | Other Construction [Member] | Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	63,346
Term Loans by Origination Year, 2019	448,004
Term Loans by Origination Year, 2018	235,925
Term Loans by Origination Year, 2017	25,957
Term Loans by Origination Year, 2016	1,481
Financing Receivable, Revolving Loans	6,858
Financing Receivable, before Allowance for Credit Loss	781,571
Commercial LHFI [Member] | Other Loans Secured by Real Estate [Member] | Other Construction [Member] | Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	13,397
Financing Receivable, before Allowance for Credit Loss	13,397
Consumer LHFI [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	202,155
Term Loans by Origination Year, 2019	346,251
Term Loans by Origination Year, 2018	268,804
Term Loans by Origination Year, 2017	130,650
Term Loans by Origination Year, 2016	138,204
Term Loans by Origination Year, Prior to 2016	423,217
Financing Receivable, Revolving Loans	422,071
Financing Receivable, before Allowance for Credit Loss	1,931,352	9,335,628
Consumer LHFI [Member] | Commercial and Industrial Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,477,896
Consumer LHFI [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		967,944
Consumer LHFI [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	38,261
Term Loans by Origination Year, 2019	43,061
Term Loans by Origination Year, 2018	21,353
Term Loans by Origination Year, 2017	7,184
Term Loans by Origination Year, 2016	2,072
Term Loans by Origination Year, Prior to 2016	869
Financing Receivable, Revolving Loans	51,760
Financing Receivable, before Allowance for Credit Loss	164,560	175,738
Consumer LHFI [Member] | Consumer Loans [Member] | Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	38,008
Term Loans by Origination Year, 2019	42,705
Term Loans by Origination Year, 2018	21,144
Term Loans by Origination Year, 2017	7,161
Term Loans by Origination Year, 2016	2,069
Term Loans by Origination Year, Prior to 2016	864
Financing Receivable, Revolving Loans	51,259
Financing Receivable, before Allowance for Credit Loss	163,210
Consumer LHFI [Member] | Consumer Loans [Member] | Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	219
Term Loans by Origination Year, 2019	330
Term Loans by Origination Year, 2018	129
Term Loans by Origination Year, 2017	3
Term Loans by Origination Year, Prior to 2016	5
Financing Receivable, Revolving Loans	326
Financing Receivable, before Allowance for Credit Loss	1,012
Consumer LHFI [Member] | Consumer Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	28
Term Loans by Origination Year, 2019	4
Term Loans by Origination Year, 2018	11
Term Loans by Origination Year, 2017	1
Financing Receivable, Revolving Loans	174
Financing Receivable, before Allowance for Credit Loss	218
Consumer LHFI [Member] | Consumer Loans [Member] | Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	6
Term Loans by Origination Year, 2019	22
Term Loans by Origination Year, 2018	69
Term Loans by Origination Year, 2017	19
Term Loans by Origination Year, 2016	3
Financing Receivable, Revolving Loans	1
Financing Receivable, before Allowance for Credit Loss	120
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	15,175
Term Loans by Origination Year, 2019	39,837
Term Loans by Origination Year, 2018	10,710
Term Loans by Origination Year, 2017	2,398
Term Loans by Origination Year, 2016	1,803
Term Loans by Origination Year, Prior to 2016	4,107
Financing Receivable, before Allowance for Credit Loss	74,030
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	15,175
Term Loans by Origination Year, 2019	39,837
Term Loans by Origination Year, 2018	10,387
Term Loans by Origination Year, 2017	2,398
Term Loans by Origination Year, 2016	1,784
Term Loans by Origination Year, Prior to 2016	3,955
Financing Receivable, before Allowance for Credit Loss	73,536
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2018	323
Term Loans by Origination Year, Prior to 2016	45
Financing Receivable, before Allowance for Credit Loss	368
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2016	19
Term Loans by Origination Year, Prior to 2016	107
Financing Receivable, before Allowance for Credit Loss	126
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	11,365
Term Loans by Origination Year, 2019	19,594
Term Loans by Origination Year, 2018	15,120
Term Loans by Origination Year, 2017	4,934
Term Loans by Origination Year, 2016	2,755
Term Loans by Origination Year, Prior to 2016	17,378
Financing Receivable, Revolving Loans	370,311
Financing Receivable, before Allowance for Credit Loss	441,457
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	11,365
Term Loans by Origination Year, 2019	19,349
Term Loans by Origination Year, 2018	14,814
Term Loans by Origination Year, 2017	4,464
Term Loans by Origination Year, 2016	2,697
Term Loans by Origination Year, Prior to 2016	16,646
Financing Receivable, Revolving Loans	367,313
Financing Receivable, before Allowance for Credit Loss	436,648
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	210
Term Loans by Origination Year, 2018	162
Term Loans by Origination Year, 2016	58
Term Loans by Origination Year, Prior to 2016	155
Financing Receivable, Revolving Loans	914
Financing Receivable, before Allowance for Credit Loss	1,499
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Past Due 90 Days or More [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, Prior to 2016	13
Financing Receivable, Revolving Loans	38
Financing Receivable, before Allowance for Credit Loss	51
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	35
Term Loans by Origination Year, 2018	144
Term Loans by Origination Year, 2017	470
Term Loans by Origination Year, Prior to 2016	564
Financing Receivable, Revolving Loans	2,046
Financing Receivable, before Allowance for Credit Loss	3,259
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	91
Term Loans by Origination Year, 2018	44
Term Loans by Origination Year, 2017	46
Term Loans by Origination Year, 2016	106
Term Loans by Origination Year, Prior to 2016	302
Financing Receivable, before Allowance for Credit Loss	589
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	91
Term Loans by Origination Year, 2018	44
Term Loans by Origination Year, 2017	46
Term Loans by Origination Year, 2016	106
Term Loans by Origination Year, Prior to 2016	302
Financing Receivable, before Allowance for Credit Loss	589
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	5
Term Loans by Origination Year, Prior to 2016	14
Financing Receivable, before Allowance for Credit Loss	19	$ 2,475,245
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	5
Term Loans by Origination Year, Prior to 2016	14
Financing Receivable, before Allowance for Credit Loss	19
Consumer LHFI [Member] | Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	137,263
Term Loans by Origination Year, 2019	243,759
Term Loans by Origination Year, 2018	221,577
Term Loans by Origination Year, 2017	116,083
Term Loans by Origination Year, 2016	131,468
Term Loans by Origination Year, Prior to 2016	400,547
Financing Receivable, before Allowance for Credit Loss	1,250,697
Consumer LHFI [Member] | Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	137,146
Term Loans by Origination Year, 2019	242,961
Term Loans by Origination Year, 2018	218,993
Term Loans by Origination Year, 2017	115,354
Term Loans by Origination Year, 2016	130,831
Term Loans by Origination Year, Prior to 2016	390,425
Financing Receivable, before Allowance for Credit Loss	1,235,710
Consumer LHFI [Member] | Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	73
Term Loans by Origination Year, 2019	85
Term Loans by Origination Year, 2018	77
Term Loans by Origination Year, 2017	123
Term Loans by Origination Year, 2016	79
Term Loans by Origination Year, Prior to 2016	1,497
Financing Receivable, before Allowance for Credit Loss	1,934
Consumer LHFI [Member] | Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Past Due 90 Days or More [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	139
Term Loans by Origination Year, Prior to 2016	390
Financing Receivable, before Allowance for Credit Loss	529
Consumer LHFI [Member] | Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	44
Term Loans by Origination Year, 2019	713
Term Loans by Origination Year, 2018	2,507
Term Loans by Origination Year, 2017	467
Term Loans by Origination Year, 2016	558
Term Loans by Origination Year, Prior to 2016	8,235
Financing Receivable, before Allowance for Credit Loss	$ 12,524

Loans Held for Investment (L_14

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Summary of LHFI by Loan Type and Credit Quality Indicator (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Financing Receivable [Abstract]
Financing receivable commercial		$ 9,659,806
Current		9,639,937	$ 9,269,775
Financing Receivable, Recorded Investment, Past Due		19,869	12,627
Nonaccrual		49,994	53,226
Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due		10,135	642	[1]
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Current		481,096	1,161,258
Financing Receivable, Recorded Investment, Past Due		1,213	636
Nonaccrual		932	897
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due		191
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Current			1,832,698
Financing Receivable, Recorded Investment, Past Due			6,405
Nonaccrual			16,810
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due	[1]		211
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Current		2,609,132	2,465,847
Financing Receivable, Recorded Investment, Past Due		1,260	1,698
Nonaccrual		7,883	7,700
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due		682
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Current		884,362	723,440
Financing Receivable, Recorded Investment, Past Due		453	8
Nonaccrual		881	1,032
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due		288
Commercial and Industrial Loans [Member]
Financing Receivable [Abstract]
Current		1,410,561	1,455,453
Financing Receivable, Recorded Investment, Past Due		2,694	668
Nonaccrual		18,181	21,775
Commercial and Industrial Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due		2,001	39	[1]
Consumer Loans [Member]
Financing Receivable [Abstract]
Current		163,312	172,650
Financing Receivable, Recorded Investment, Past Due		1,248	2,980
Nonaccrual		120	108
Consumer Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due		217	392	[1]
State and Other Political Subdivision Loans [Member]
Financing Receivable [Abstract]
Current		931,359	963,789
Financing Receivable, Recorded Investment, Past Due		177	76
Nonaccrual		4,049	4,079
State and Other Political Subdivision Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due		177
Other Loans [Member]
Financing Receivable [Abstract]
Current			494,640
Financing Receivable, Recorded Investment, Past Due			156
Nonaccrual			825
Commercial LHFI [Member]
Financing Receivable [Abstract]
Financing receivable commercial		7,728,454	7,348,158
Commercial LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			1,090,914
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			123,033
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial		2,610,373	2,475,090
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			723,785
Commercial LHFI [Member] | Commercial and Industrial Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		1,413,255	1,477,896
Commercial LHFI [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		931,536	967,944
Commercial LHFI [Member] | Other Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial			489,496
Commercial LHFI [Member] | Pass Categories 1-6 [Member]
Financing Receivable [Abstract]
Financing receivable commercial			7,178,617
Commercial LHFI [Member] | Pass Categories 1-6 [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			1,075,146
Commercial LHFI [Member] | Pass Categories 1-6 [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			116,592
Commercial LHFI [Member] | Pass Categories 1-6 [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial		2,550,088	2,430,761
Commercial LHFI [Member] | Pass Categories 1-6 [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			721,238
Commercial LHFI [Member] | Pass Categories 1-6 [Member] | Commercial and Industrial Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		1,368,786	1,407,837
Commercial LHFI [Member] | Pass Categories 1-6 [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		922,468	957,948
Commercial LHFI [Member] | Pass Categories 1-6 [Member] | Other Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial			469,095
Commercial LHFI [Member] | Special Mention Category 7 [Member]
Financing Receivable [Abstract]
Financing receivable commercial			9,049
Commercial LHFI [Member] | Special Mention Category 7 [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			45
Commercial LHFI [Member] | Special Mention Category 7 [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial		11,982
Commercial LHFI [Member] | Special Mention Category 7 [Member] | Commercial and Industrial Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		1,683	909
Commercial LHFI [Member] | Special Mention Category 7 [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		4,000	4,650
Commercial LHFI [Member] | Special Mention Category 7 [Member] | Other Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial			3,445
Commercial LHFI [Member] | Substandard Category 8 [Member]
Financing Receivable [Abstract]
Financing receivable commercial			159,163
Commercial LHFI [Member] | Substandard Category 8 [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			15,726
Commercial LHFI [Member] | Substandard Category 8 [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			6,355
Commercial LHFI [Member] | Substandard Category 8 [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial		47,735	44,001
Commercial LHFI [Member] | Substandard Category 8 [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			2,547
Commercial LHFI [Member] | Substandard Category 8 [Member] | Commercial and Industrial Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		42,265	68,262
Commercial LHFI [Member] | Substandard Category 8 [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		5,068	5,346
Commercial LHFI [Member] | Substandard Category 8 [Member] | Other Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial			16,926
Commercial LHFI [Member] | Doubtful Category 9 [Member]
Financing Receivable [Abstract]
Financing receivable commercial			1,329
Commercial LHFI [Member] | Doubtful Category 9 [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			42
Commercial LHFI [Member] | Doubtful Category 9 [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			41
Commercial LHFI [Member] | Doubtful Category 9 [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial		568	328
Commercial LHFI [Member] | Doubtful Category 9 [Member] | Commercial and Industrial Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		521	888
Commercial LHFI [Member] | Doubtful Category 9 [Member] | Other Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial			30
Consumer LHFI [Member]
Financing Receivable [Abstract]
Financing receivable commercial		1,931,352	9,335,628
Current			1,961,967
Nonaccrual			16,057
Subtotal			1,987,470
Consumer LHFI [Member] | Past Due 30-89 Days [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due			8,842
Consumer LHFI [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due			604
Consumer LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			1,162,791
Current			71,413
Nonaccrual			132
Subtotal			71,877
Consumer LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 30-89 Days [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due			332
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			1,855,913
Current			1,710,930
Nonaccrual			15,817
Subtotal			1,732,880
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30-89 Days [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due			5,922
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing Receivable, Recorded Investment, Past Due			211
Consumer LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial		19	2,475,245
Current			155
Subtotal			155
Consumer LHFI [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable [Abstract]
Financing receivable commercial			724,480
Current			695
Subtotal			695
Consumer LHFI [Member] | Commercial and Industrial Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial			1,477,896
Consumer LHFI [Member] | Consumer Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial		164,560	175,738
Current			172,649
Nonaccrual			108
Subtotal			175,738
Consumer LHFI [Member] | Consumer Loans [Member] | Past Due 30-89 Days [Member]
Financing Receivable [Abstract]
Financing receivable commercial		1,012
Financing Receivable, Recorded Investment, Past Due			2,588
Consumer LHFI [Member] | Consumer Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable [Abstract]
Financing receivable commercial		$ 218
Financing Receivable, Recorded Investment, Past Due			393
Consumer LHFI [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial			967,944
Consumer LHFI [Member] | Other Loans [Member]
Financing Receivable [Abstract]
Financing receivable commercial			495,621
Current			6,125
Subtotal			$ 6,125
[1]	Past due 90 days or more but still accruing interest.

Loans Held for Investment (L_15

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Summary of Trustmark's Portfolio Segments, Loan Classes, Loan Pools and the ACL Methodology and Loss Drivers (Details)	6 Months Ended
	Jun. 30, 2020
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | 1 -4 Family Residential Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Prime Rate, National GDP
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Lots and Development [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Prime Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Unimproved Land [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Prime Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | All Other Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Prime Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | All Other Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Prime Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Consumer 1-4 Family - 1st Liens [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Prime Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Nonresidential Owner- Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Unemployment, National GDP
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Nonresidential Owner- Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Unemployment, National GDP
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Nonowner-Occupied - Hotel/Motel [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Vacancy Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Nonowner-Occupied - Office [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Vacancy Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Nonowner-Occupied- Retail [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Vacancy Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Nonowner-Occupied- Senior Living/ Nursing Homes [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Vacancy Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Nonowner-occupied - All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Vacancy Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Nonresidential Owner- Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Unemployment, National GDP
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Nonowner-occupied - All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Vacancy Rate, Southern Unemployment
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Nonresidential Nonowner- Occupied - Apartments [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Southern Vacancy Rate, Southern Unemployment
Other Loans Secured by Real Estate [Member] | Other Construction [Member] | Other Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	WARM
Loss Drivers	Prime Rate, National Unemployment
Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Trustmark Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	WARM
Loss Drivers	Southern Unemployment
Commercial and Industrial Loans [Member] | Commercial and Industrial Loans [Member] | Commercial and Industrial - Non-Working Capital [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Trustmark historical data
Commercial and Industrial Loans [Member] | Commercial and Industrial Loans [Member] | Commercial and Industrial - Working Capital [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Trustmark historical data
Commercial and Industrial Loans [Member] | Commercial and Industrial Loans [Member] | Credit Cards [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	WARM
Loss Drivers	Trustmark call report data
Consumer Loans [Member] | Consumer Loans [Member] | All Other Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Prime Rate, Southern Unemployment
Consumer Loans [Member] | Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	WARM
Loss Drivers	Trustmark call report data
Consumer Loans [Member] | Consumer Loans [Member] | Overdrafts [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	Loss Rate
Loss Drivers	Trustmark historical data
State and Other Political Subdivision Loans [Member] | State and Other Political Subdivision Loans [Member] | Obligations of State and Political Subdivisions [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Moody's Bond Default Study
Other Commercial Loans [Member] | Other Commercial Loans [Member] | Commercial and Industrial - Non-Working Capital [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Trustmark historical data
Other Commercial Loans [Member] | Other Commercial Loans [Member] | Commercial and Industrial - Working Capital [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Trustmark historical data
Other Commercial Loans [Member] | Other Commercial Loans [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Methodology	DCF
Loss Drivers	Prime Rate, Southern Unemployment

Loans Held for Investment (L_16

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Summary of Balance in Allowance for Loan Losses (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss				$ 5,500
Total	[1]	$ 119,188		84,277
Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		2,318		5,459
Collectively Evaluated for Credit Loss		116,870		78,818
Total		119,188	$ 100,564	84,277	$ 80,399	$ 79,005	$ 79,290
Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		42,129		41,217
Collectively Evaluated for Credit Loss		9,617,677		9,294,411
Total		9,659,806		9,335,628	80,399		79,290
Commercial and Industrial Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		21		707
Collectively Evaluated for Credit Loss		12,529		25,285
Total		12,550	14,564	25,992
Commercial and Industrial Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		16,363		23,458
Collectively Evaluated for Credit Loss		1,396,892		1,454,438
Total		1,413,255		1,477,896	27,618		27,359
Consumer Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss		6,397		3,379
Total		6,397	6,596	3,379
Consumer Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss				21
Collectively Evaluated for Credit Loss		164,560		175,717
Total		164,560		175,738	3,248		2,890
State and Other Political Subdivision Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		1,779		1,809
Collectively Evaluated for Credit Loss		1,635		420
Total		3,414	3,441	2,229
State and Other Political Subdivision Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		4,049		4,079
Collectively Evaluated for Credit Loss		927,487		963,865
Total		931,536		967,944	438		990
Other Commercial Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		518
Collectively Evaluated for Credit Loss		5,934
Total		6,452	6,020	5,303
Other Commercial Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		5,764
Collectively Evaluated for Credit Loss		558,682
Total		564,446
Other Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss				553
Collectively Evaluated for Credit Loss				4,750
Total				5,303
Other Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss				784
Collectively Evaluated for Credit Loss				494,837
Total				495,621	5,836		6,194
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss		11,940		8,260
Total		11,940		8,260
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		1,948		626
Collectively Evaluated for Credit Loss		480,361		1,162,165
Total		482,309		1,162,791	6,931		7,390
Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss		12,716
Total		12,716	11,711	5,888
Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		496
Collectively Evaluated for Credit Loss		562,332
Total		562,828
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss				2,355
Collectively Evaluated for Credit Loss		36,417		23,803
Total		36,417	28,127	26,158
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		11,966		6,717
Collectively Evaluated for Credit Loss		2,598,426		2,468,528
Total		2,610,392		2,475,245	24,248		22,376
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss		7,600		4,024
Total		7,600	5,273	4,024
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		63		68
Collectively Evaluated for Credit Loss		884,752		724,412
Total		884,815		724,480	3,721		3,450
Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss				35
Collectively Evaluated for Credit Loss				8,897
Total				8,932
Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss				5,464
Collectively Evaluated for Credit Loss				1,850,449
Total				1,855,913	$ 8,359		$ 8,641
Other Loans Secured by Real Estate [Member] | Other Construction [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss		10,803
Total		10,803	7,711	1,889
Other Loans Secured by Real Estate [Member] | Other Construction [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss		794,968
Total		794,968
Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss		10,899
Total		10,899	$ 8,042	$ 3,044
Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss		1,480
Collectively Evaluated for Credit Loss		1,249,217
Total		$ 1,250,697
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Loans Held for Investment (L_17

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Change in Allowance for Loan Losses (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	[1]		$ 84,277		$ 84,277
FASB ASU 2016-13 Adoption Adjustment			19,949
PCL	[1]	$ 18,185		$ 2,486	38,766	$ 4,097
Balance at end of period	[1]	119,188			119,188
Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		100,564	84,277	79,005	84,277	79,290
FASB ASU 2016-13 Adoption Adjustment					(1,217)
Loans charged-off		(1,870)		(2,937)	(7,415)	(6,970)
Recoveries		2,309		1,845	4,777	3,982
Net (charge-offs) recoveries		439		(1,092)	(2,638)	(2,988)
PCL		18,185		2,486	38,766	4,097
Balance at end of period		119,188	100,564	80,399	119,188	80,399
Allowance for Credit Losses, ACL [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			8,260		8,260
Balance at end of period		11,940			11,940
Allowance for Credit Losses, ACL [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Commercial LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		9,079	6,371		6,371
FASB ASU 2016-13 Adoption Adjustment					(188)
Loans charged-off		(7)			(7)
Recoveries		92			186
PCL		2,776			5,578
Balance at end of period		11,940	9,079		11,940
Allowance for Credit Losses, ACL [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		11,711	5,888		5,888
FASB ASU 2016-13 Adoption Adjustment					4,188
Loans charged-off		(36)			(100)
Recoveries		83			146
PCL		958			2,594
Balance at end of period		12,716	11,711		12,716
Allowance for Credit Losses, ACL [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			8,932		8,932
Allowance for Credit Losses, ACL [Member] | Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		8,042	3,044		3,044
FASB ASU 2016-13 Adoption Adjustment					2,891
Loans charged-off					(19)
Recoveries		13			106
PCL		2,844			4,877
Balance at end of period		10,899	8,042		10,899
Allowance for Credit Losses, ACL [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		28,127	26,158		26,158
FASB ASU 2016-13 Adoption Adjustment					(8,179)
Loans charged-off					(2,448)
Recoveries		445			506
PCL		7,845			20,380
Balance at end of period		36,417	28,127		36,417
Allowance for Credit Losses, ACL [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		5,273	4,024		4,024
FASB ASU 2016-13 Adoption Adjustment					(765)
Loans charged-off					(8)
Recoveries		12			18
PCL		2,315			4,331
Balance at end of period		7,600	5,273		7,600
Allowance for Credit Losses, ACL [Member] | Commercial and Industrial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		14,564	25,992		25,992
FASB ASU 2016-13 Adoption Adjustment					(8,964)
Loans charged-off		(297)			(1,279)
Recoveries		191			733
PCL		(1,908)			(3,932)
Balance at end of period		12,550	14,564		12,550
Allowance for Credit Losses, ACL [Member] | Other Construction [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		7,711	1,889		1,889
FASB ASU 2016-13 Adoption Adjustment					3,202
Recoveries		21			40
PCL		3,071			5,672
Balance at end of period		10,803	7,711		10,803
Allowance for Credit Losses, ACL [Member] | Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		6,596	3,379		3,379
FASB ASU 2016-13 Adoption Adjustment					2,059
Loans charged-off		(671)			(1,361)
Recoveries		468			941
PCL		4			1,379
Balance at end of period		6,397	6,596		6,397
Allowance for Credit Losses, ACL [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		3,441	2,229		2,229
FASB ASU 2016-13 Adoption Adjustment					2,455
PCL		(27)			(1,270)
Balance at end of period		3,414	3,441		3,414
Allowance for Credit Losses, ACL [Member] | Other Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period		6,020	5,303		5,303
FASB ASU 2016-13 Adoption Adjustment					2,084
Loans charged-off		(859)			(2,193)
Recoveries		984			2,101
PCL		307			(843)
Balance at end of period		6,452	6,020		6,452
Allowance for Credit Losses, ACL [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			5,303		5,303
Allowance for Credit Losses, ACL [Member] | ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
LHFI					(3,039)
Allowance for loan losses, acquired loans transfer					815
Acquired loans ACL adjustment					1,007
Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			9,335,628		9,335,628	79,290
Loans charged-off						(6,970)
Recoveries						3,982
PCL						4,097
Balance at end of period		9,659,806		80,399	9,659,806	80,399
Allowance for Loan Losses, LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			1,162,791		1,162,791	7,390
Loans charged-off						(35)
Recoveries						577
PCL						(1,001)
Balance at end of period		482,309		6,931	482,309	6,931
Allowance for Loan Losses, LHFI [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at end of period		562,828			562,828
Allowance for Loan Losses, LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			1,855,913		1,855,913	8,641
Loans charged-off						(281)
Recoveries						336
PCL						(337)
Balance at end of period				8,359		8,359
Allowance for Loan Losses, LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at end of period		1,250,697			1,250,697
Allowance for Loan Losses, LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			2,475,245		2,475,245	22,376
Loans charged-off						(34)
Recoveries						30
PCL						1,876
Balance at end of period		2,610,392		24,248	2,610,392	24,248
Allowance for Loan Losses, LHFI [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			724,480		724,480	3,450
Recoveries						16
PCL						255
Balance at end of period		884,815		3,721	884,815	3,721
Allowance for Loan Losses, LHFI [Member] | Commercial and Industrial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			1,477,896		1,477,896	27,359
Loans charged-off						(2,831)
Recoveries						329
PCL						2,761
Balance at end of period		1,413,255		27,618	1,413,255	27,618
Allowance for Loan Losses, LHFI [Member] | Other Construction [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at end of period		794,968			794,968
Allowance for Loan Losses, LHFI [Member] | Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			175,738		175,738	2,890
Loans charged-off						(1,269)
Recoveries						954
PCL						673
Balance at end of period		164,560		3,248	164,560	3,248
Allowance for Loan Losses, LHFI [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			967,944		967,944	990
PCL						(552)
Balance at end of period		931,536		438	931,536	438
Allowance for Loan Losses, LHFI [Member] | Other Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at end of period		$ 564,446			564,446
Allowance for Loan Losses, LHFI [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			$ 495,621		$ 495,621	6,194
Loans charged-off						(2,520)
Recoveries						1,740
PCL						422
Balance at end of period				$ 5,836		$ 5,836
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Acquired Loans - Additional Inf

Acquired Loans - Additional Information (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Dec. 31, 2019		Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable Allowance For Credit Losses [Line Items]
Acquired loans		$ 72,601
Allowance for loan losses, acquired loans		$ 815	[1]	$ 1,398	$ 1,297	$ 1,231
ASU 2016-13 [Member] | Purchased Credit Deteriorated (PCD) Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Acquired loans	$ 72,600
Allowance for loan losses, acquired loans	$ 815
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Acquired Loans - Schedule of Ac

Acquired Loans - Schedule of Acquired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019		Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 72,601
Less allowance for loan losses, acquired loans	815	[1]	$ 1,398	$ 1,297	$ 1,231
Net acquired loans	71,786
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	4,771
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	17,525
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	38,206
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	3,946
Commercial and Industrial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	5,035
Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	520
Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 2,598
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Acquired Loans - Changes in the

Acquired Loans - Changes in the Carrying Value of Acquired Loans (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended		12 Months Ended
		Mar. 31, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Carrying value of acquired loans [Abstract]
Carrying value, net, beginning		$ 71,786	$ 71,786
FASB ASU 2016-13 adoption adjustment		19,949
Accretion to interest income				$ 2,983
Carrying value, net, ending					$ 71,786
Acquired Not ASC 310-30 [Member]
Carrying value of acquired loans [Abstract]
Carrying value, net, beginning	[1]	0	0	2,811	2,811
Transfers	[1],[2]				(2,926)
Accretion to interest income	[1]		0		115
Payments received, net	[1]		0		0
Other	[1],[3]		0		0
Change in allowance for loan losses, acquired loans	[1]		0		0
Carrying value, net, ending	[1]		0		0
Acquired Not ASC 310-30 [Member] | ASU 2016-13 [Member]
Carrying value of acquired loans [Abstract]
FASB ASU 2016-13 adoption adjustment	[1]		0
Acquired Impaired [Member]
Carrying value of acquired loans [Abstract]
Carrying value, net, beginning		$ 71,786	71,786	$ 102,890	102,890
Transfers	[2]				0
Accretion to interest income			0		5,532
Payments received, net			0		(37,230)
Other	[3]		0		178
Change in allowance for loan losses, acquired loans			0		416
Carrying value, net, ending			0		$ 71,786
Acquired Impaired [Member] | ASU 2016-13 [Member]
Carrying value of acquired loans [Abstract]
FASB ASU 2016-13 adoption adjustment			$ (71,786)
[1]	“Acquired Not ASC 310-30” loans consist of loans that are not in scope for FASB ASC Subtopic 310-30.
[2]	“Acquired Not ASC 310-30”
[3]	Includes miscellaneous timing adjustments as well as acquired loan terminations through foreclosure, charge-off and other terminations.

Acquired Loans - Changes in Acc

Acquired Loans - Changes in Accretable Yield of Acquired Loans (Details) - USD ($) $ in Thousands		6 Months Ended		12 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Change in accretable difference on acquired loans [Abstract]
Accretable yield at beginning of period		$ (14,816)	$ (17,722)	$ (17,722)
FASB ASU 2016-13 adoption adjustment		$ 14,816
Accretion to interest income			2,983
Disposals, net			1,114
Reclassification from nonaccretable difference	[1]		(2,280)
Accretable yield at end of period			$ (15,905)	$ (14,816)
[1]	Reclassifications from nonaccretable difference are due to lower loss expectations and improvements in expected cash flows.

Acquired Loans - Components of

Acquired Loans - Components of the Allowance for Loan Losses on Acquired Loans (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
		Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		$ 1,297	$ 815	[1]	$ 1,231
FASB ASU 2016-13 adoption adjustment			$ (815)
Net (charge-offs) recoveries		(5)			(17)
Provision for loan losses, acquired loans	[1]	106			184
Balance at end of period		$ 1,398			$ 1,398
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Acquired Loans - Acquired Loans

Acquired Loans - Acquired Loans by Loan Class and Credit Quality Indicator (Details) $ in Thousands	Dec. 31, 2019USD ($)
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	$ 71,786
Acquired Loans, Aging [Abstract]
Current	70,305
Acquired Loans, Past Due	2,296
Nonaccrual	0	[1]
Total Acquired Loans	72,601
Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	1,307	[2]
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current	4,639
Acquired Loans, Past Due	132
Nonaccrual	0	[1]
Total Acquired Loans	4,771
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	38	[2]
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current	16,332
Acquired Loans, Past Due	1,193
Nonaccrual	0	[1]
Total Acquired Loans	17,525
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	366	[2]
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current	37,319
Acquired Loans, Past Due	887
Nonaccrual	0	[1]
Total Acquired Loans	38,206
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	851	[2]
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current	3,893
Acquired Loans, Past Due	53
Nonaccrual	0	[1]
Total Acquired Loans	3,946
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	52	[2]
Commercial and Industrial Loans [Member]
Acquired Loans, Aging [Abstract]
Current	5,035
Acquired Loans, Past Due	0
Nonaccrual	0	[1]
Total Acquired Loans	5,035
Commercial and Industrial Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0	[2]
Consumer Loans [Member]
Acquired Loans, Aging [Abstract]
Current	489
Acquired Loans, Past Due	31
Nonaccrual	0	[1]
Total Acquired Loans	520
Consumer Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0	[2]
Other Loans [Member]
Acquired Loans, Aging [Abstract]
Current	2,598
Acquired Loans, Past Due	0
Nonaccrual	0	[1]
Total Acquired Loans	2,598
Other Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0	[2]
Commercial LHFI [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	57,785
Commercial LHFI [Member] | Pass Categories 1-6 [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	44,922
Commercial LHFI [Member] | Special Mention Category 7 [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	42
Commercial LHFI [Member] | Substandard Category 8 [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	10,819
Commercial LHFI [Member] | Doubtful Category 9 [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	2,002
Commercial LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	4,214
Commercial LHFI [Member] | Construction, Land Development and Other Land [Member] | Pass Categories 1-6 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	4,022
Commercial LHFI [Member] | Construction, Land Development and Other Land [Member] | Substandard Category 8 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	192
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	3,786
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Pass Categories 1-6 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	3,164
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Special Mention Category 7 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	42
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Substandard Category 8 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	580
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	38,206
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Pass Categories 1-6 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	27,848
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Substandard Category 8 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	9,972
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Doubtful Category 9 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	386
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	3,946
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Pass Categories 1-6 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	3,878
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Substandard Category 8 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	68
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Doubtful Category 9 [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	0
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	5,035
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Pass Categories 1-6 [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	3,419
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Doubtful Category 9 [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	1,616
Commercial LHFI [Member] | Other Loans [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	2,598
Commercial LHFI [Member] | Other Loans [Member] | Pass Categories 1-6 [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	2,591
Commercial LHFI [Member] | Other Loans [Member] | Substandard Category 8 [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans	7
Consumer LHFI [Member]
Acquired Loans, Aging [Abstract]
Current	13,795
Subtotal	14,816
Total Acquired Loans	72,601
Consumer LHFI [Member] | Past Due 30-89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	740
Consumer LHFI [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	281
Consumer LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current	463
Subtotal	557
Total Acquired Loans	4,771
Consumer LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 30-89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	94
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current	12,843
Subtotal	13,739
Total Acquired Loans	17,525
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30-89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	615
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	281
Consumer LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Total Acquired Loans	38,206
Consumer LHFI [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Total Acquired Loans	3,946
Consumer LHFI [Member] | Commercial and Industrial Loans [Member]
Acquired Loans, Aging [Abstract]
Total Acquired Loans	5,035
Consumer LHFI [Member] | Consumer Loans [Member]
Acquired Loans, Aging [Abstract]
Current	489
Subtotal	520
Total Acquired Loans	520
Consumer LHFI [Member] | Consumer Loans [Member] | Past Due 30-89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	31
Consumer LHFI [Member] | Other Loans [Member]
Acquired Loans, Aging [Abstract]
Total Acquired Loans	$ 2,598
[1]	Acquired loans not accounted for under FASB ASC Subtopic 310-30.
[2]	Past due 90 days or more but still accruing interest.

Acquired Loans - Aging Analysis

Acquired Loans - Aging Analysis of Past Due and Nonaccrual Acquired Loans (Details) $ in Thousands	Dec. 31, 2019USD ($)
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	$ 2,296
Nonaccrual	0	[1]
Current	70,305
Acquired Loans	72,601
Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	843
Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	146
Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	1,307	[2]
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	132
Nonaccrual	0	[1]
Current	4,639
Acquired Loans	4,771
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	94
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	38	[2]
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	1,193
Nonaccrual	0	[1]
Current	16,332
Acquired Loans	17,525
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	696
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	131
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	366	[2]
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	887
Nonaccrual	0	[1]
Current	37,319
Acquired Loans	38,206
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	36
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	851	[2]
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	53
Nonaccrual	0	[1]
Current	3,893
Acquired Loans	3,946
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	1
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	52	[2]
Commercial and Industrial Loans [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Nonaccrual	0	[1]
Current	5,035
Acquired Loans	5,035
Commercial and Industrial Loans [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Commercial and Industrial Loans [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Commercial and Industrial Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0	[2]
Consumer Loans [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	31
Nonaccrual	0	[1]
Current	489
Acquired Loans	520
Consumer Loans [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	16
Consumer Loans [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	15
Consumer Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0	[2]
Other Loans [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Nonaccrual	0	[1]
Current	2,598
Acquired Loans	2,598
Other Loans [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Other Loans [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	0
Other Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	$ 0	[2]
[1]	Acquired loans not accounted for under FASB ASC Subtopic 310-30.
[2]	Past due 90 days or more but still accruing interest.

Mortgage Banking - Schedule of

Mortgage Banking - Schedule of Activity in the Mortgage Servicing Rights (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Mortgage servicing rights [Abstract]
Balance at beginning of period	$ 79,394	$ 95,596
Origination of servicing assets	12,396	6,075
Change in fair value [Abstract]
Due to market changes	(27,158)	(17,072)
Due to run-off	(6,821)	(5,316)
Balance at end of period	$ 57,811	$ 79,283

Mortgage Banking - Additional I

Mortgage Banking - Additional Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)CPR	Jun. 30, 2019USD ($)CPR
Schedule of changes in the reserve for mortgage loan [Abstract]
Assumed average prepayment speed | CPR	17	12
Average discount rate (in hundredths)	9.58%	10.04%
Mortgage servicing rights [Abstract]
Residential mortgage loans sold	$ 1,103,000	$ 488,100
Gains on sales of residential mortgage loans	$ 48,400	12,500
Period of putback response	60 days
Reserve for mortgage loan servicing putback expenses	$ 500	$ 702

Mortgage Banking - Schedule o_2

Mortgage Banking - Schedule of Mortgage Loans Sold and Serviced for Others (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Mortgage Loans On Real Estate [Line Items]
Total mortgage loans sold and serviced for others	$ 7,392,640	$ 7,157,234
Federal National Mortgage Association [Member]
Mortgage Loans On Real Estate [Line Items]
Total mortgage loans sold and serviced for others	4,535,557	4,411,914
Government National Mortgage Association [Member]
Mortgage Loans On Real Estate [Line Items]
Total mortgage loans sold and serviced for others	2,774,839	2,652,782
Federal Home Loan Mortgage Corporation [Member]
Mortgage Loans On Real Estate [Line Items]
Total mortgage loans sold and serviced for others	64,232	73,134
Other [Member]
Mortgage Loans On Real Estate [Line Items]
Total mortgage loans sold and serviced for others	$ 18,012	$ 19,404

Other Real Estate - Changes and

Other Real Estate - Changes and Gains (Losses), Net on Other Real Estate (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Reconciliation Of Carrying Amount Of Real Estate Investments Roll Forward
Balance at beginning of period	$ 29,248	$ 34,668
Additions	406	2,101
Disposals	(10,534)	(3,859)
Write-downs	(844)	(1,667)
Balance at end of period	18,276	31,243
Gains (losses), net on the sale of other real estate included in other real estate expense	$ (255)	$ 246

Other Real Estate - Other Real

Other Real Estate - Other Real Estate, By Type of Property (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Other real estate, excluding covered other real estate [Line Items]
Total other real estate	$ 18,276	$ 29,248	$ 31,243	$ 34,668
Construction, Land Development And Other Land Properties [Member]
Other real estate, excluding covered other real estate [Line Items]
Total other real estate	8,341	11,482
1 - 4 Family Residential Properties [Member]
Other real estate, excluding covered other real estate [Line Items]
Total other real estate	1,992	3,453
Nonfarm, Nonresidential Properties [Member]
Other real estate, excluding covered other real estate [Line Items]
Total other real estate	$ 7,943	$ 14,313

Other Real Estate - Other Rea_2

Other Real Estate - Other Real Estate, By Geographic Location (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Other real estate, excluding covered other real estate [Line Items]
Total other real estate		$ 18,276	$ 29,248	$ 31,243	$ 34,668
Alabama [Member]
Other real estate, excluding covered other real estate [Line Items]
Total other real estate		4,766	8,133
Florida [Member]
Other real estate, excluding covered other real estate [Line Items]
Total other real estate		3,665	5,877
Mississippi [Member]
Other real estate, excluding covered other real estate [Line Items]
Total other real estate	[1]	9,408	14,919
Tennessee [Member]
Other real estate, excluding covered other real estate [Line Items]
Total other real estate	[2]	$ 437	$ 319
[1]	Mississippi includes Central and Southern Mississippi Regions.
[2]	Tennessee includes Memphis, Tennessee and Northern Mississippi Regions.

Other Real Estate - Additional

Other Real Estate - Additional information (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Reconciliation Of Carrying Amount Of Real Estate Investments Roll Forward
Foreclosed residential real estate properties recorded as a result of obtaining physical possession of property	$ 2,000	$ 3,500
Consumer mortgage loans and that formal foreclosure proceedings are in process	$ 333	$ 953

Leases - Components of Net Leas

Leases - Components of Net Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Finance leases
Amortization of right-of-use assets	$ 481	$ 642	$ 978	$ 1,145
Interest on lease liabilities	65	80	132	161
Operating lease cost	1,289	1,289	2,579	2,589
Short-term lease cost	111	123	220	203
Variable lease cost	332	346	679	690
Sublease income	(63)	(82)	(162)	(169)
Net lease cost	$ 2,215	$ 2,398	$ 4,426	$ 4,619

Leases - Cash Payments Included

Leases - Cash Payments Included in Measurement of Lease Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Finance leases
Operating cash flows included in operating activities	$ 132	$ 526
Financing cash flows included in payments under finance lease obligations	905	1,035
Operating leases
Operating cash flows (fixed payments) included in other operating activities, net	2,493	2,481
Operating cash flows (liability reduction) included in other operating activities, net	$ 1,949	$ 1,875

Leases - Balance Sheet Informat

Leases - Balance Sheet Information and Weighted-Average Lease Terms and Discount Rates Related to Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Leases [Abstract]
Finance lease right-of-use assets, net of accumulated depreciation	$ 8,348	$ 9,326
Finance lease liabilities	8,616	9,520
Operating lease right-of-use assets	29,819	31,182
Operating lease liabilities	$ 31,076	$ 32,354
Weighted-average lease term
Finance leases	8 years 6 months 29 days	8 years 7 months 13 days
Operating leases	8 years 8 months 19 days	9 years 18 days
Weighted-average discount rate
Finance leases	3.05%	3.01%
Operating leases	3.49%	3.51%

Leases - Future Minimum Rental

Leases - Future Minimum Rental Commitments Under Finance and Operating Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Leases [Abstract]
Finance leases, 2020 (excluding the six months ended June 30, 2020)	$ 1,740
Finance leases, 2021	1,617
Finance leases, 2022	1,350
Finance leases, 2023	549
Finance leases, 2024	582
Thereafter	4,161
Finance leases, total minimum lease payments	9,999
Finance leases, imputed interest	(1,383)
Finance lease liabilities	8,616	$ 9,520
Operating leases, 2020 (excluding the six months ended June 30, 2020)	4,890
Operating leases, 2021	4,355
Operating leases, 2022	4,139
Operating leases, 2023	4,102
Operating leases, 2024	3,994
Thereafter	14,738
Operating leases, total minimum lease payments	36,218
Operating leases, imputed interest	(5,142)
Operating lease liabilities	$ 31,076	$ 32,354

Deposits - Deposits Summary (De

Deposits - Deposits Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Deposits [Abstract]
Noninterest-bearing demand	$ 3,880,540	$ 2,891,215
Interest-bearing demand	4,037,460	3,125,914
Savings	4,075,127	3,590,509
Time	1,512,346	1,637,919
Total deposits	$ 13,505,473	$ 11,245,557

Securities Sold Under Repurch_3

Securities Sold Under Repurchase Agreement - Additional Information (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Securities sold under repurchase agreements, secured by securities carrying amount	$ 93.7	$ 105.6

Securities Sold Under Repurch_4

Securities Sold Under Repurchase Agreements - Schedule of Securities Sold Under Repurchase Agreements (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Securities sold under repurchase agreements by collateral pledged
Total securities sold under repurchase agreements	$ 53,522	$ 53,572
Other Residential Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Securities sold under repurchase agreements by collateral pledged
Total securities sold under repurchase agreements	23,780	24,282
Commercial Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Securities sold under repurchase agreements by collateral pledged
Total securities sold under repurchase agreements	$ 29,742	$ 29,290

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue From Contract With Customer [Abstract]
Other real estate sales, net gains (losses)	$ (185)	$ 124	$ (255)	$ 246

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Summary of Noninterest Income Disaggregated by Reportable Operating Segment and Revenue Stream (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		$ 6,397	$ 10,379	$ 16,429	$ 20,644
Bank card and other fees		7,717	8,004	13,072	15,195
Mortgage banking, net		33,745	10,295	61,228	13,737
Insurance commissions		11,868	11,089	23,418	21,960
Wealth management		7,571	7,742	16,108	15,225
Other, net		2,213	2,130	4,520	4,369
Total Noninterest Income		69,511	49,639	134,775	91,130
Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		6,397	10,379	16,429	20,644
Bank card and other fees		6,557	7,181	13,289	14,070
Insurance commissions		11,868	11,089	23,418	21,960
Wealth management		7,571	7,742	16,108	15,225
Other, net		1,420	2,360	3,232	4,844
Total Noninterest Income		33,813	38,751	72,476	76,743
Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Bank card and other fees	[1]	1,160	823	(217)	1,125
Mortgage banking, net	[1]	33,745	10,295	61,228	13,737
Other, net	[1]	793	(230)	1,288	(475)
Total Noninterest Income	[1]	35,698	10,888	62,299	14,387
General Banking Segment [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		6,380	10,357	16,392	20,597
Bank card and other fees		7,709	7,985	13,058	15,152
Mortgage banking, net		33,745	10,295	61,228	13,737
Wealth management		79	97	165	188
Other, net		2,138	2,074	4,384	4,047
Total Noninterest Income		50,051	30,808	95,227	53,721
General Banking Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		6,380	10,357	16,392	20,597
Bank card and other fees		6,549	7,162	13,275	14,027
Wealth management		79	97	165	188
Other, net		1,354	2,333	3,118	4,577
Total Noninterest Income		14,362	19,949	32,950	39,389
General Banking Segment [Member] | Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Bank card and other fees	[1]	1,160	823	(217)	1,125
Mortgage banking, net	[1]	33,745	10,295	61,228	13,737
Other, net	[1]	784	(259)	1,266	(530)
Total Noninterest Income	[1]	35,689	10,859	62,277	14,332
Wealth Management Segment [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		17	22	37	47
Bank card and other fees		8	19	14	43
Wealth management		7,492	7,645	15,943	15,037
Other, net		33	54	72	316
Total Noninterest Income		7,550	7,740	16,066	15,443
Wealth Management Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		17	22	37	47
Bank card and other fees		8	19	14	43
Wealth management		7,492	7,645	15,943	15,037
Other, net		24	25	50	261
Total Noninterest Income		7,541	7,711	16,044	15,388
Wealth Management Segment [Member] | Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Other, net	[1]	9	29	22	55
Total Noninterest Income	[1]	9	29	22	55
Insurance Segment [Member]
Revenue From Contract With Customer [Line Items]
Insurance commissions		11,868	11,089	23,418	21,960
Other, net		42	2	64	6
Total Noninterest Income		11,910	11,091	23,482	21,966
Insurance Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Insurance commissions		11,868	11,089	23,418	21,960
Other, net		42	2	64	6
Total Noninterest Income		$ 11,910	$ 11,091	$ 23,482	$ 21,966
[1]	Noninterest income not in scope for FASB ASC Topic 606 includes customer derivatives revenue and miscellaneous credit card fee income within bank card and other fees; mortgage banking, net; amortization of tax credits, accretion of the FDIC indemnification asset, cash surrender value on various life insurance policies, earnings on Trustmark’s non-qualified deferred compensation plans, other partnership investments and rental income within other, net; and security

Defined Benefit and Other Pos_3

Defined Benefit and Other Postretirement Benefits - Net Periodic Benefit Cost for Plan and Continuing plan (Details) - Trustmark Capital Accumulation Plan [Member] - Trustmark Corporation Pension Plan for Certain Employees of Acquired Financial Institutions [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net periodic benefit cost [Abstract]
Service cost	$ 63	$ 53	$ 127	$ 106
Interest cost	61	90	121	180
Expected return on plan assets	(39)	(50)	(77)	(101)
Recognized net loss due to lump sum settlements	40	63	40	94
Recognized net actuarial loss	82	93	163	186
Net periodic benefit cost	$ 207	$ 249	$ 374	$ 465

Defined Benefit and Other Pos_4

Defined Benefit and Other Postretirement Benefits - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
The Continuing Plan [Member] | Scenario Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Trustmark's minimum required contribution to the Trustmark Corporation Pension Plan for Certain Employees of Acquired Financial Institutions	$ 306

Defined Benefit and Other Pos_5

Defined Benefit and Other Postretirement Benefits - Net Periodic Benefit Cost (Details) - Supplemental Retirement Plan [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net periodic benefit cost [Abstract]
Service cost	$ 20	$ 28	$ 39	$ 55
Interest cost	387	501	801	1,042
Amortization of prior service cost	38	62	75	125
Recognized net actuarial loss	236	154	482	316
Net periodic benefit cost	$ 681	$ 745	$ 1,397	$ 1,538

Stock and Incentive Compensat_3

Stock and Incentive Compensation - Additional Information (Details)	6 Months Ended
	Jun. 30, 2020
Performance Based Award [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Return on average tangible equity, performance measure	100.00%
Total shareholder return, performance measure	100.00%
Time-Vested Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years

Stock and Incentive Compensat_4

Stock and Incentive Compensation - Summary of Stock Plan Activity (Details) - Stock and Incentive Compensation Plan [Member] - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Performance Based Awards and Units [Member]
Shares [Roll Forward]
Nonvested shares, beginning of period (in shares)	147,533	149,914
Granted (in shares)		53,450
Released from restriction (in shares)		(36,357)
Forfeited (in shares)	(1,025)	(20,499)
Nonvested shares, end of period (in shares)	146,508	146,508
Time-Vested Awards and Units [Member]
Shares [Roll Forward]
Nonvested shares, beginning of period (in shares)	329,732	300,006
Granted (in shares)	6,040	121,560
Released from restriction (in shares)	(28,065)	(107,506)
Forfeited (in shares)	(3,014)	(9,367)
Nonvested shares, end of period (in shares)	304,693	304,693

Stock and Incentive Compensat_5

Stock and Incentive Compensation - Compensation Expense for Awards and Units Under Stock Plan (Details) - Stock and Incentive Compensation Plan [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Compensation expense [Abstract]
Recognized compensation expense	$ 1,274	$ 1,279	$ 2,668	$ 2,281
Performance Awards and Units [Member]
Compensation expense [Abstract]
Recognized compensation expense	456	481	(57)	562
Time-Vested Awards and Units [Member]
Compensation expense [Abstract]
Recognized compensation expense	$ 818	$ 798	$ 2,725	$ 1,719

Contingencies - Additional Info

Contingencies - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Loss Contingencies [Line Items]
Unused commitments to extend credit	$ 4,391	$ 4,146
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Potential exposure to credit loss in the event of nonperformance	$ 105.7	103.6
Letters of credit, maturity term - maximum	3 years
Collateral held, fair value	$ 21.8	$ 30.3

Contingencies - Summary of Chan

Contingencies - Summary of Changes in ACL on Off-balance Sheet Credit Exposures (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
		Jun. 30, 2020	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Balance at beginning of period		$ 36,421	$ 0	[1]
FASB ASU 2016-13 adoption adjustment		0	29,638
Credit loss expense related to off-balance sheet credit exposures	[1]	6,242	13,025
Balance at end of period	[1]	$ 42,663	$ 42,663
[1]	Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach.  Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.

Earnings Per Share (EPS) - Weig

Earnings Per Share (EPS) - Weighted-Average Shares Used to Calculate Basic and Diluted EPS (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Basic shares	63,416	64,678	63,586	64,957
Dilutive shares	139	137	136	132
Diluted shares	63,555	64,815	63,722	65,089

Earnings Per Share (EPS) - We_2

Earnings Per Share (EPS) - Weighted-Average Antidilutive Stock Awards Excluded from Determining Diluted EPS (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Weighted-average antidilutive stock awards (in shares)	11	23	63	78

Statements of Cash Flows (Detai

Statements of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Statement of cash flows specific transaction amounts [Abstract]
Income taxes paid	$ 23,309	$ 5,336
Interest expense paid on deposits and borrowings	26,808	43,004
Noncash transfers from loans to other real estate	406	2,101
Finance right-of-use assets resulting from lease liabilities		10,698
Operating right-of-use assets resulting from lease liabilities	$ 671	$ 32,762

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended	37 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Jun. 30, 2020	Apr. 01, 2020	Dec. 31, 2019	Apr. 01, 2019	Mar. 11, 2016
Stockholders Equity [Line items]
Capital conservation buffer rate					2.50%		2.50%
Stock Repurchase Program 1 [Member] | Common Stock [Member]
Stockholders Equity [Line items]
Amount of stock authorized for repurchase									$ 100
Repurchase shares of common stock		1,200,000		3,200,000
Repurchase shares of common stock, value		$ 36.9		$ 100
Stock Repurchase Program 2 [Member] | Common Stock [Member]
Stockholders Equity [Line items]
Amount of stock authorized for repurchase								$ 100
Repurchase shares of common stock	887,000		1,500,000
Repurchase shares of common stock, value	$ 27.5		$ 47.2
Stock Repurchase Program 3 [Member] | Common Stock [Member]
Stockholders Equity [Line items]
Amount of stock authorized for repurchase						$ 100

Shareholders' Equity - Table of

Shareholders' Equity - Table of Actual Regulatory Capital Amounts and Ratios (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Trustmark Corporation [Member] | Common Equity Tier 1 Capital (to Risk Weighted Assets) [Member]
Common Equity Tier One Risk Based Capital [Abstract]
Actual Regulatory Capital Amount		$ 1,317,378	$ 1,312,668
Actual Regulatory Capital Ratio		11.42%	11.93%
Minimum Regulatory Capital Required Ratio		7.00%	7.00%
Minimum Regulatory Provision to be Well-Capitalized Ratio	[1]
Trustmark Corporation [Member] | Tier 1 Capital (to Risk Weighted Assets) [Member]
Tier 1 Capital (to Risk Weighted Assets) [Abstract]
Actual Regulatory Capital Amount		$ 1,377,378	$ 1,372,668
Actual Regulatory Capital Ratio		11.94%	12.48%
Minimum Regulatory Capital Required Ratio		8.50%	8.50%
Minimum Regulatory Provision to be Well-Capitalized Ratio	[1]
Trustmark Corporation [Member] | Total Capital (to Risk Weighted Assets) [Member]
Total Capital (to Risk Weighted Assets) [Abstract]
Actual Regulatory Capital Amount		$ 1,499,887	$ 1,457,760
Actual Regulatory Capital Ratio		13.00%	13.25%
Minimum Regulatory Capital Required Ratio		10.50%	10.50%
Minimum Regulatory Provision to be Well-Capitalized Ratio	[1]
Trustmark Corporation [Member] | Tier 1 Leverage (to Average Assets) [Member]
Tier 1 Leverage (to Average Assets) [Abstract]
Actual Regulatory Capital Amount		$ 1,377,378	$ 1,372,668
Actual Regulatory Capital Ratio		9.08%	10.48%
Minimum Regulatory Capital Required Ratio		4.00%	4.00%
Minimum Regulatory Provision to be Well-Capitalized Ratio	[1]
Trustmark National Bank [Member] | Common Equity Tier 1 Capital (to Risk Weighted Assets) [Member]
Common Equity Tier One Risk Based Capital [Abstract]
Actual Regulatory Capital Amount		$ 1,353,727	$ 1,352,893
Actual Regulatory Capital Ratio		11.73%	12.30%
Minimum Regulatory Capital Required Ratio		7.00%	7.00%
Minimum Regulatory Provision to be Well-Capitalized Ratio		6.50%	6.50%
Trustmark National Bank [Member] | Tier 1 Capital (to Risk Weighted Assets) [Member]
Tier 1 Capital (to Risk Weighted Assets) [Abstract]
Actual Regulatory Capital Amount		$ 1,353,727	$ 1,352,893
Actual Regulatory Capital Ratio		11.73%	12.30%
Minimum Regulatory Capital Required Ratio		8.50%	8.50%
Minimum Regulatory Provision to be Well-Capitalized Ratio		8.00%	8.00%
Trustmark National Bank [Member] | Total Capital (to Risk Weighted Assets) [Member]
Total Capital (to Risk Weighted Assets) [Abstract]
Actual Regulatory Capital Amount		$ 1,476,236	$ 1,437,985
Actual Regulatory Capital Ratio		12.80%	13.07%
Minimum Regulatory Capital Required Ratio		10.50%	10.50%
Minimum Regulatory Provision to be Well-Capitalized Ratio		10.00%	10.00%
Trustmark National Bank [Member] | Tier 1 Leverage (to Average Assets) [Member]
Tier 1 Leverage (to Average Assets) [Abstract]
Actual Regulatory Capital Amount		$ 1,353,727	$ 1,352,893
Actual Regulatory Capital Ratio		8.94%	10.35%
Minimum Regulatory Capital Required Ratio		4.00%	4.00%
Minimum Regulatory Provision to be Well-Capitalized Ratio		5.00%	5.00%
[1]	n/a

Shareholders' Equity - Net Chan

Shareholders' Equity - Net Change in Components of Accumulated Other Comprehensive Income (Loss) and the Related Tax Effects (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax amount	$ 3,822	$ 21,465	$ 45,554	$ 41,151
Other comprehensive income (loss), tax (expense) benefit	(955)	(5,366)	(11,389)	(10,288)
Other comprehensive income (loss), before reclassifications, net of tax amount			33,595	30,556
Reclassification from accumulated other comprehensive income, current period, net of tax amount			570	307
Other comprehensive income (loss), net of tax amount	2,867	16,099	34,165	30,863
Securities Available for Sale and Transferred Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, before tax amount	2,648	20,079	43,155	38,903
Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, before tax amount	778	1,256	1,639	2,003
Other comprehensive income (loss), before tax amount	3,426	21,335	44,794	40,906
Other comprehensive income (loss), before reclassifications, tax (expense) benefit	(662)	(5,020)	(10,789)	(9,726)
Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, tax (expense) benefit	(195)	(314)	(410)	(501)
Other comprehensive income (loss), tax (expense) benefit	(857)	(5,334)	(11,199)	(10,227)
Other comprehensive income (loss), before reclassifications, net of tax amount	1,986	15,059	32,366	29,177
Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, net of tax amount	583	942	1,229	1,502
Other comprehensive income (loss), net of tax amount	2,569	16,001	33,595	30,679
Net Change in Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from accumulated other comprehensive income, current period, before tax amount	38	62	75	125
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit	(10)	(15)	(19)	(31)
Reclassification from accumulated other comprehensive income, current period, net of tax amount	28	47	56	94
Recognized Net Loss Due to Lump Sum Settlements [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from accumulated other comprehensive income, current period, before tax amount	40	63	40	94
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit	(10)	(16)	(10)	(23)
Reclassification from accumulated other comprehensive income, current period, net of tax amount	30	47	30	71
Change in Net Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from accumulated other comprehensive income, current period, before tax amount	318	247	645	502
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit	(78)	(61)	(161)	(126)
Reclassification from accumulated other comprehensive income, current period, net of tax amount	240	186	484	376
Pension and Other Postretirement Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from accumulated other comprehensive income, current period, before tax amount	396	372	760	721
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit	(98)	(92)	(190)	(180)
Reclassification from accumulated other comprehensive income, current period, net of tax amount	298	280	570	541
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, before tax amount	0	(101)	0	(164)
Reclassification from accumulated other comprehensive income, current period, before tax amount	0	(141)	0	(312)
Other comprehensive income (loss), before tax amount	0	(242)	0	(476)
Other comprehensive income (loss), before reclassifications, tax (expense) benefit	0	25	0	41
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit	0	35	0	78
Other comprehensive income (loss), tax (expense) benefit	0	60	0	119
Other comprehensive income (loss), before reclassifications, net of tax amount	0	(76)	0	(123)
Reclassification from accumulated other comprehensive income, current period, net of tax amount	0	(106)	0	(234)
Other comprehensive income (loss), net of tax amount	$ 0	$ (182)	$ 0	$ (357)

Shareholders' Equity - Changes

Shareholders' Equity - Changes in Balances of Component of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 1,652,399	$ 1,587,028	$ 1,660,702	$ 1,591,453
Other comprehensive income (loss), before reclassifications, net of tax amount			33,595	30,556
Amounts reclassified from accumulated other comprehensive income (loss)			570	307
Other comprehensive income (loss), net of tax amount	2,867	16,099	34,165	30,863
Balance	1,673,944	1,618,550	1,673,944	1,618,550
Securities Available for Sale and Transferred Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(8,017)	(43,824)
Other comprehensive income (loss), before reclassifications, net of tax amount			33,595	30,679
Other comprehensive income (loss), net of tax amount			33,595	30,679
Balance	25,578	(13,145)	25,578	(13,145)
Defined Benefit Pension Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(15,583)	(12,324)
Amounts reclassified from accumulated other comprehensive income (loss)			570	541
Other comprehensive income (loss), net of tax amount			570	541
Balance	(15,013)	(11,783)	(15,013)	(11,783)
Cash Flow Hedge Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance				469
Other comprehensive income (loss), before reclassifications, net of tax amount				(123)
Amounts reclassified from accumulated other comprehensive income (loss)				(234)
Other comprehensive income (loss), net of tax amount				(357)
Balance		112		112
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	7,698	(40,915)	(23,600)	(55,679)
Balance	$ 10,565	$ (24,816)	$ 10,565	$ (24,816)

Fair Value - Financial Assets a

Fair Value - Financial Assets and Liabilities Measured at Fair Value Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 1,884,153	$ 1,602,404
Loans held for sale	355,089	226,347
Mortgage servicing rights	57,811	79,394	$ 79,283	$ 95,596
U.S. Government Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	19,898	22,327
Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	11,176	25,465
Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,884,153	1,602,404
Loans held for sale	355,089	226,347
Mortgage servicing rights	57,811	79,394
Other assets - derivatives	58,880	17,956
Other liabilities - derivatives	4,994	6,063
Recurring Basis [Member] | U.S. Government Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	19,898	22,327
Recurring Basis [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	11,176	25,465
Recurring Basis [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,853,079	1,554,612
Level 1 [Member] | Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Loans held for sale	0	0
Mortgage servicing rights	0	0
Other assets - derivatives	843	244
Other liabilities - derivatives	335	4,414
Level 1 [Member] | Recurring Basis [Member] | U.S. Government Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Level 1 [Member] | Recurring Basis [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Level 1 [Member] | Recurring Basis [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Level 2 [Member] | Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,884,153	1,602,404
Loans held for sale	355,089	226,347
Mortgage servicing rights	0	0
Other assets - derivatives	43,707	16,273
Other liabilities - derivatives	4,659	1,649
Level 2 [Member] | Recurring Basis [Member] | U.S. Government Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	19,898	22,327
Level 2 [Member] | Recurring Basis [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	11,176	25,465
Level 2 [Member] | Recurring Basis [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,853,079	1,554,612
Level 3 [Member] | Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Loans held for sale	0	0
Mortgage servicing rights	57,811	79,394
Other assets - derivatives	14,330	1,439
Other liabilities - derivatives	0	0
Level 3 [Member] | Recurring Basis [Member] | U.S. Government Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Level 3 [Member] | Recurring Basis [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Level 3 [Member] | Recurring Basis [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 0	$ 0

Fair Value - Changes in Level 3

Fair Value - Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis (Details) - Recurring Basis [Member] - Level 3 [Member] - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019
MSR [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		$ 79,394	$ 95,596
Total net (loss) gain included in Mortgage banking, net	[1]	(33,979)	(22,388)
Additions		12,396	6,075
Sales		0	0
Ending Balance		57,811	79,283
The amount of total gains (losses) for the period included in earnings that are attributable to the change in unrealized gains or losses still held, end of period		(27,158)	(17,072)
Other Assets - Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		1,439	1,187
Total net (loss) gain included in Mortgage banking, net	[1]	22,382	3,889
Additions		0	0
Sales		(9,491)	(2,531)
Ending Balance		14,330	2,545
The amount of total gains (losses) for the period included in earnings that are attributable to the change in unrealized gains or losses still held, end of period		$ 12,897	$ 678
[1]	Total net (loss) gain included in Mortgage banking, net relating to the MSR includes changes in fair value due to market changes and due to run-off.

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Outstanding balances in collateral dependent related to allowance for credit losses	$ 42,100		$ 42,100
Collateral dependent related to allowance for credit losses	2,300		2,300
Outstanding balances in impaired loans					$ 41,200
Impaired loans, related allowance					5,500
Foreclosed assets remeasured after initial recognition			3,200	$ 8,800
Write-downs of allowance for foreclosed assets after initial recognition			873	1,100
Noninterest gain (loss) Mortgage banking, net for changes in fair value of LHFS	(445)	$ 2,200	7,300	2,900
Interest earned on LHFS included in Interest and fees on LHFS and LHFI	1,500	$ 1,300	2,800	$ 2,400
GNMA optional repurchase loans	$ 121,400		$ 121,400		$ 57,100

Fair Value - Carrying Amounts a

Fair Value - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity		$ 660,048	$ 738,099
Net LHFI and PPP loans		9,540,618	9,251,351
Acquired loans			71,786
Deposits		13,505,473	11,245,557
Federal funds purchased and securities sold under repurchase agreements		70,255	256,020
Other borrowings		152,860	85,396
Junior subordinated debt securities		61,856	61,856
Level 2 [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments		1,026,640	358,916
Securities held to maturity		660,048	738,099
Deposits		13,505,473	11,245,557
Federal funds purchased and securities sold under repurchase agreements		70,255	256,020
Other borrowings		152,860	85,396
Junior subordinated debt securities		61,856	61,856
Level 2 [Member] | Estimate Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments		1,026,640	358,916
Securities held to maturity		690,561	746,202
Deposits		13,512,248	11,250,071
Federal funds purchased and securities sold under repurchase agreements		70,255	256,020
Other borrowings		152,861	85,374
Junior subordinated debt securities		45,155	50,722
Level 3 [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net LHFI and PPP loans		10,480,401	9,251,351
Acquired loans	[1]	0	71,786
Level 3 [Member] | Estimate Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net LHFI and PPP loans		10,500,218	9,235,674
Acquired loans	[1]	$ 0	$ 71,786
[1]	Upon adoption of FASB ASC Topic 326 at January 1, 2020, Trustmark elected to account for its existing acquired loans as purchased credit deteriorated loans included within the LHFI portfolio.  See Note 4 – Acquired Loans for additional details.

Fair Value - Fair Value and the

Fair Value - Fair Value and the Contractual Principal Outstanding of the LHFS (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair value and the contractual principal outstanding of the LHFS [Abstract]
Fair value of LHFS	$ 233,687	$ 169,285
LHFS contractual principal outstanding	221,365	164,420
Fair value less unpaid principal	$ 12,322	$ 4,865

Derivative Financial Instrume_3

Derivative Financial Instruments - Additional Information (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020USD ($)Contract	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)Contract	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)Contract	Apr. 04, 2013USD ($)
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Period for which cash flow hedges will be used to hedge quarterly interest payments			5 years
Derivative inception date			Dec. 31, 2014
Derivative maturity date			Dec. 31, 2019
Description of variable rate basis for derivative			three-month LIBOR
Ineffectiveness related to interest rate swap designated as a cash flow hedge			$ 0
Accumulated net, after tax gain included in accumulated other comprehensive (loss)					$ 0
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Junior Subordinated Debentures [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total notional amount						$ 60,000,000
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Three-month LIBOR [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Swap fixed interest rate to be paid	1.66%		1.66%
Derivatives not Designated as Hedging Instruments [Member] | Beneficiary [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Number of risk participation agreements | Contract	3		3		3
Aggregate notional amount of credit risk participation agreements	$ 41,700,000		$ 41,700,000		$ 37,600,000
Derivatives not Designated as Hedging Instruments [Member] | Guarantor [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Number of risk participation agreements | Contract	10		10		10
Aggregate notional amount of credit risk participation agreements	$ 73,400,000		$ 73,400,000		$ 79,300,000
Derivatives not Designated as Hedging Instruments [Member] | Mortgage Servicing Rights Hedge [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total notional amount	385,000,000		385,000,000		564,000,000
Net (negative) positive ineffectiveness on MSR fair value	(2,000,000)	$ (53,000)	7,900,000	$ (4,800,000)
Derivatives not Designated as Hedging Instruments [Member] | Interest Rate Swap [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total notional amount	978,100,000		978,100,000		893,100,000
Termination value of derivatives	1,900,000		1,900,000		1,000,000
Collateral Posted	2,100,000		2,100,000
Derivatives not Designated as Hedging Instruments [Member] | Forward Contracts [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet obligations	359,500,000		359,500,000		209,000,000
Valuation adjustment			(2,600,000)		(486,000)
Derivatives not Designated as Hedging Instruments [Member] | Interest Rate Lock Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet obligations	$ 427,300,000		427,300,000		92,100,000
Valuation adjustment			$ 14,300,000		$ 1,400,000

Derivative Financial Instrume_4

Derivative Financial Instruments - Fair Value of Derivative Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	$ 43,579	$ 16,209
Fair value of derivative liability	1,932	1,122
Derivatives not Designated as Hedging Instruments [Member] | Future Contracts [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	509
Derivatives not Designated as Hedging Instruments [Member] | Future Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability		2,654
Derivatives not Designated as Hedging Instruments [Member] | Credit Risk Participation Agreement [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	128	64
Derivatives not Designated as Hedging Instruments [Member] | Credit Risk Participation Agreement [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	153	41
Derivatives not Designated as Hedging Instruments [Member] | Forward Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	2,574	486
Derivatives not Designated as Hedging Instruments [Member] | Exchange Traded Purchased Options [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	334	244
Derivatives not Designated as Hedging Instruments [Member] | OTC Written Options (Rate Locks) [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	14,330	1,439
Derivatives not Designated as Hedging Instruments [Member] | Interest Rate Swap [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative asset	43,579	16,209
Derivatives not Designated as Hedging Instruments [Member] | Interest Rate Swap [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	1,932	1,122
Derivatives not Designated as Hedging Instruments [Member] | Exchange Traded Written Options [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liability	$ 335	$ 1,760

Derivative Financial Instrume_5

Derivative Financial Instruments - Effects of Derivative Instruments on Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivatives in Hedging Relationships [Member] | Accumulated Other Comprehensive Income (Loss) and Other Interest Expense [Member]
Derivatives, Fair Value [Line Items]
Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) and recognized in other interest expense		$ 141		$ 312
Derivatives not Designated as Hedging Instruments [Member] | Mortgage Banking, Net [Member]
Derivatives, Fair Value [Line Items]
Amount of gain (loss) recognized in mortgage banking, net	$ 12,395	7,944	$ 45,881	12,797
Derivatives not Designated as Hedging Instruments [Member] | Bank Card and Other Fees [Member]
Derivatives, Fair Value [Line Items]
Amount of gain (loss) recognized in bank card and other fees	$ (76)	$ (487)	$ (1,736)	$ (743)

Derivative Financial Instrume_6

Derivative Financial Instruments - Schedule of Amount Included in Other Comprehensive Income (Loss) for Derivative Instruments Designated as Hedges of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivatives, Fair Value [Line Items]
Amount of gain (loss) recognized in other comprehensive income (loss), net of tax	$ 0	$ (76)	$ 0	$ (123)
Derivatives in Hedging Relationships [Member]
Derivatives, Fair Value [Line Items]
Amount of gain (loss) recognized in other comprehensive income (loss), net of tax		$ (76)		$ (123)

Derivative Financial Instrume_7

Derivative Financial Instruments - Information about Financial Instruments that are Eligible for Offset in the Consolidated Balance Sheets (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Offsetting Derivative Assets
Gross Amounts of Recognized Assets, Offsetting of Derivative Assets	$ 43,579	$ 16,209
Gross Amounts Offset in the Statement of Financial Position, Offsetting of Derivative Assets	0	0
Net Amounts of Assets presented in the Statement of Financial Position, Offsetting of Derivative Assets	43,579	16,209
Financial Instruments, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Assets	(1)	0
Cash Collateral Received, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Assets	0	0
Net Amount, Offsetting of Derivative Assets	43,578	16,209
Offsetting Derivative Liabilities
Gross Amounts of Recognized Liabilities, Offsetting of Derivative Liabilities	1,932	1,122
Gross Amounts Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities	0	0
Net Amounts of Liabilities presented in the Statement of Financial Position, Offsetting of Derivative Liabilities	1,932	1,122
Financial Instruments, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities	(1)	0
Cash Collateral Posted, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities	(1,931)	(1,390)
Net Amount, Offsetting of Derivative Liabilities	$ 0	$ (268)

Segment Information - Additiona

Segment Information - Additional Information (Details)	6 Months Ended
	Jun. 30, 2020Segment
Segment Reporting [Abstract]
Number of segments in which the business operates	3

Segment Information - Schedule

Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net interest income	$ 105,000		$ 107,724		$ 208,952	$ 212,532
Provision for credit losses	18,185		2,592		38,766	4,281
Noninterest income	69,511		49,639		134,775	91,130
Noninterest expense	118,659		106,101		242,469	212,122
Income Before Income Taxes	37,667		48,670		62,492	87,259
Income taxes	5,517		6,530		8,124	11,780
Net Income	32,150	$ 22,218	42,140	$ 33,339	54,368	75,479
Selected Financial Information
Total assets	15,692,079		13,548,958		15,692,079	13,548,958	$ 13,497,877
Depreciation and amortization	10,660		9,786		19,656	19,123
General Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	103,376		105,897		205,779	208,902
Provision for credit losses	18,188		2,596		36,562	4,289
Noninterest income	50,051		30,808		95,227	53,721
Noninterest expense	103,355		90,093		209,805	180,108
Income Before Income Taxes	31,884		44,016		54,639	78,226
Income taxes	4,093		5,362		6,184	9,517
Net Income	27,791		38,654		48,455	68,709
Selected Financial Information
Total assets	15,378,653		13,161,680		15,378,653	13,161,680
Depreciation and amortization	10,422		9,592		19,216	18,731
Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest income	1,576		1,772		3,080	3,520
Provision for credit losses	(3)		(4)		2,204	(8)
Noninterest income	7,550		7,740		16,066	15,443
Noninterest expense	6,944		7,727		15,460	15,390
Income Before Income Taxes	2,185		1,789		1,482	3,581
Income taxes	547		447		371	891
Net Income	1,638		1,342		1,111	2,690
Selected Financial Information
Total assets	232,467		313,398		232,467	313,398
Depreciation and amortization	67		68		134	137
Insurance [Member]
Segment Reporting Information [Line Items]
Net interest income	48		55		93	110
Noninterest income	11,910		11,091		23,482	21,966
Noninterest expense	8,360		8,281		17,204	16,624
Income Before Income Taxes	3,598		2,865		6,371	5,452
Income taxes	877		721		1,569	1,372
Net Income	2,721		2,144		4,802	4,080
Selected Financial Information
Total assets	80,959		73,880		80,959	73,880
Depreciation and amortization	$ 171		$ 126		$ 306	$ 255

Accounting Policies Recently _3

Accounting Policies Recently Adopted and Pending Accounting Pronouncements - Additional Information (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Jun. 30, 2020	Jun. 30, 2020
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Increase to allowance for credit loss on off-balance sheet credit exposures		$ 0	$ 29,638
ASU 2016-13 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Decrease to loans held for investment, allowance for credit loss	$ 3,000
Increase to allowance for credit loss on off-balance sheet credit exposures	29,600
One-time cumulative effect adjustment through retained earnings, before tax	26,600
One-time cumulative effect adjustment through retained earnings, net of tax	$ 19,900