Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
OPERATING ACTIVITIES
Net income	$ 256,412	$ 271,156	$ 254,904
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	48,962	47,220	49,038
Provision for credit losses	14,074	(32,704)	74,973
Loss (gain) on sale of investments	278	(15,498)	(54,806)
Net accretion of investment securities and assets	(39,031)	(52,781)	(56,771)
Net amortization on borrowings	313	1,257	541
Stock-based compensation expense	15,317	15,868	13,197
Gain on sale of premises and equipment, net of impairment	0	(591)	(14)
Gain on sale of foreclosed assets and other real estate owned	(390)	(932)	(391)
Gain on sale of mortgage loans held for sale	(7,945)	(36,434)	(44,864)
Gain on sale of other intangibles	0	0	(301)
Gain on sale of branches	0	(5,316)	(8,094)
Gain on sale of loans	(282)	0	0
Fair value write-down of closed branches	0	0	434
Deferred income taxes	14,933	10,937	(122)
Income from bank owned life insurance	(11,164)	(9,477)	(7,206)
Loss from early retirement of TruPS	365	0	0
Originations of mortgage loans held for sale	(497,815)	(1,034,716)	(1,206,818)
Proceeds from sale of mortgage loans held for sale	538,630	1,190,891	1,172,406
Changes in assets and liabilities:
Interest receivable	(22,107)	4,423	(10,846)
Other assets	(7,214)	(33,495)	(7,480)
Accrued interest and other liabilities	10,417	(50,620)	50,508
Income taxes payable	8,445	8,592	(15,745)
Net cash provided by operating activities	322,198	277,780	202,543
INVESTING ACTIVITIES
Net change in loans	(1,900,325)	2,333,893	1,327,248
Proceeds from sale of loans	73,746	28,033	49,736
Decrease in due from banks - time	1,087	292	2,975
Purchases of premises and equipment, net	(35,268)	(47,861)	(13,272)
Proceeds from sale of premises and equipment	0	5,621	369
Proceeds from sale of foreclosed assets and other real estate owned	4,754	21,983	10,788
Proceeds from sale of available-for-sale securities	0	342,577	1,717,364
Proceeds from maturities of available-for-sale securities	1,137,923	1,001,669	2,346,930
Purchases of available-for-sale securities	(261,375)	(5,266,148)	(4,140,963)
Proceeds from maturities of held-to-maturity securities	86,229	15,712	13,970
Purchases of held-to-maturity securities	(331,273)	(708,580)	(308,854)
Proceeds from bank owned life insurance death benefits	1,873	3,814	2,018
Purchases of bank owned life insurance	0	(160,000)	0
Cash received in business combinations, net	276,396	25,425	0
Disposition of assets and liabilities held for sale	0	(134,166)	181,560
Net cash (used in) provided by investing activities	(946,233)	(2,537,736)	1,189,869
FINANCING ACTIVITIES
Net change in deposits	462,530	847,494	1,086,713
Repayments of subordinated debentures	(56,189)	(1,563)	(7,442)
Dividends paid on preferred stock	0	(47)	(52)
Dividends paid on common stock	(94,096)	(78,845)	(74,593)
Net change in other borrowed funds	(516,726)	(80,254)	45,983
Net change in federal funds purchased and securities sold under agreements to repurchase	(25,000)	(116,562)	148,966
Net shares (cancelled) issued under stock compensation plans	(5,033)	290	(4,087)
Shares issued under employee stock purchase plan	1,151	1,170	956
Repurchase of common stock	(111,133)	(132,459)	(113,327)
Retirement of preferred stock	0	(767)	0
Net cash (used in) provided by financing activities	(344,496)	438,457	1,083,117
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(968,531)	(1,821,499)	2,475,529
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	1,650,653	3,472,152	996,623
CASH AND CASH EQUIVALENTS, END OF YEAR	$ 682,122	$ 1,650,653	$ 3,472,152