Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019
Operating Activities
Net income per consolidated statements of income		$ 108,808	$ 116,514
Adjustments to reconcile net income to net cash provided by operating activities:
Credit loss expense, net	[1]	50,547	7,180
Depreciation and amortization		30,000	29,585
Net amortization of securities		8,458	5,699
Gains on sales of loans, net		(61,464)	(17,556)
Compensation expense, long-term incentive plan		3,907	3,553
Deferred income tax provision		(20,600)	(6,400)
Proceeds from sales of loans held for sale		1,869,187	943,309
Purchases and originations of loans held for sale		(1,976,190)	(1,078,222)
Originations of mortgage servicing rights		(20,728)	(11,431)
Earnings on bank-owned life insurance		(3,845)	(4,239)
Net change in other assets		(53,141)	(31,241)
Net change in other liabilities		5,667	(1,625)
Other operating activities, net		30,367	26,874
Net cash from operating activities		(29,027)	(18,000)
Investing Activities
Proceeds from maturities, prepayments and calls of securities held to maturity		128,367	125,652
Proceeds from maturities, prepayments and calls of securities available for sale		465,568	306,630
Purchases of securities available for sale		(758,008)	(9,744)
Net proceeds from bank-owned life insurance		592	4,159
Net change in federal funds sold and securities purchased under reverse repurchase agreements		(50)	830
Net change in member bank stock		281	(285)
Net change in LHFI and PPP loans		(1,384,833)	(370,781)
Purchases of premises and equipment		(15,634)	(11,335)
Proceeds from sales of premises and equipment		548	2,374
Proceeds from sales of other real estate		11,434	6,698
Purchases of software		(6,050)	(9,541)
Investments in tax credit and other partnerships		(4,458)	(3,426)
Purchase of insurance book of business		(3,097)	(347)
Net cash used in business acquisition		(4,834)	0
Net cash from investing activities		(1,570,174)	40,884
Financing Activities
Net change in deposits		1,976,856	(110,228)
Net change in federal funds purchased and securities sold under repurchase agreements		(102,186)	326,241
Net change in short-term borrowings		4,272	344
Payments on long-term FHLB advances		(39)	(51)
Payments under finance lease obligations		(1,319)	(1,509)
Common stock dividends		(44,079)	(44,924)
Repurchase and retirement of common stock		(27,538)	(54,416)
Shares withheld to pay taxes, long-term incentive plan		(1,094)	(1,639)
Net cash from financing activities		1,804,873	113,818
Net change in cash and cash equivalents		205,672	136,702
Cash and cash equivalents at beginning of period		358,916	349,561
Cash and cash equivalents at end of period		$ 564,588	$ 486,263

[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.