Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Operating Activities
Net income per consolidated statements of income	$ 149,584	$ 105,630		$ 108,411
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses, net	16,988	7,699		14,714
Depreciation and amortization	38,940	38,471		36,613
Net amortization of securities	9,181	10,964		9,664
Securities (gains) losses, net	0	(15)	[1]	310	[1]
Gains on sales of loans, net	(21,615)	(18,933)		(20,531)
Deferred income tax provision	11,740	26,068		18,000
Proceeds from sales of loans held for sale	1,114,020	1,197,821		1,404,852
Purchases and originations of loans held for sale	(1,052,339)	(1,179,187)		(1,392,155)
Originations of mortgage servicing rights	(15,759)	(15,860)		(16,745)
Earnings on bank-owned life insurance	(5,358)	(5,025)		(4,883)
Net change in other assets	(1,891)	23,451		(20,129)
Net change in other liabilities	(1,277)	9,093		7,284
Other operating activities, net	(3,016)	6,430		2,932
Net cash from operating activities	239,198	206,607		148,337
Investing Activities
Proceeds from maturities, prepayments and calls of securities held to maturity	149,308	174,976		277,373
Proceeds from maturities, prepayments and calls of securities available for sale	423,617	467,194		486,915
Proceeds from sales of securities available for sale	0	27,682		24,693
Purchases of securities held to maturity	0	(69,989)		(239,446)
Purchases of securities available for sale	(23,901)	(346,159)		(547,112)
Net proceeds from bank-owned life insurance	1,824	3,623		2,585
Net change in federal funds sold and securities purchased under reverse repurchase agreements	(215)	6,785		(250)
Net change in member bank stock	35,451	4,474		(8,386)
Net change in loans	(140,710)	(608,886)		(677,296)
Purchases of premises and equipment	(14,644)	(13,219)		(10,208)
Proceeds from sales of premises and equipment	772	8,377		6,799
Proceeds from sales of other real estate	20,502	26,849		42,809
Purchases of software	(13,195)	(5,498)		(8,024)
Investments in tax credit and other partnerships	(22)	(5,296)		(116)
Net cash used in business acquisition	0	(19,775)		0
Net cash from investing activities	438,787	(348,862)		(649,664)
Financing Activities
Net change in deposits	786,899	355,342		467,782
Net change in federal funds purchased and securities sold under repurchase agreements	(419,356)	(69,990)		98,775
Net change in short-term borrowings	(905,396)	(67,451)		(150,748)
Payments on long-term FHLB advances	(67)	(65)		(94)
Proceeds from long-term FHLB advances	0	0		250,000
Redemption of junior subordinated debt securities	0	(3,000)		0
Payment of subordinated debt	0	0		(50,000)
Common stock dividends	(62,425)	(62,795)		(62,666)
Repurchase and retirement of common stock	(62,421)	0		(750)
Shares withheld to pay taxes, long-term incentive plan	(1,426)	(1,724)		(1,017)
Net cash from financing activities	(664,192)	150,317		551,282
Net change in cash and cash equivalents	13,793	8,062		49,955
Cash and cash equivalents at beginning of year	335,768	327,706		277,751
Cash and cash equivalents at end of year	$ 349,561	$ 335,768		$ 327,706

[1] Trustmark elected the modified retrospective approach of adoption; therefore, prior period balances are presented under legacy GAAP and may not be comparable to current year presentation.