Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
OPERATING ACTIVITIES
Net income	$ 175,057	$ 256,412	$ 271,156
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	47,877	48,962	47,220
Provision for credit losses	42,028	14,074	(32,704)
Loss (gain) on sale of investments	20,609	278	(15,498)
Net amortization (accretion) of investment securities and assets	14,982	(39,031)	(52,781)
Net amortization on borrowings	152	313	1,257
Stock-based compensation expense	12,189	15,317	15,868
Gain on sale of premises and equipment, net of impairment	0	0	(591)
Gain on sale of foreclosed assets and other real estate owned	(182)	(390)	(932)
Gain on sale of mortgage loans held for sale	(7,379)	(7,945)	(36,434)
Gain on sale of branches	0	0	(5,316)
Gain on sale of loans	0	(282)	0
Deferred income taxes	(2,460)	14,933	10,937
Income from bank owned life insurance	(12,905)	(11,164)	(9,477)
Loss from early retirement of TruPS	0	365	0
Originations of mortgage loans held for sale	(262,901)	(497,815)	(1,034,716)
Proceeds from sale of mortgage loans held for sale	264,393	538,630	1,190,891
Changes in assets and liabilities:
Interest receivable	(19,538)	(22,107)	4,423
Other assets	263,969	(7,214)	(33,495)
Accrued interest and other liabilities	(3,908)	10,417	(50,620)
Income taxes payable	8,996	8,445	8,592
Net cash provided by operating activities	540,979	322,198	277,780
INVESTING ACTIVITIES
Net change in loans	(786,775)	(1,900,325)
Net change in loans			2,333,893
Proceeds from sale of loans	69,760	73,746	28,033
Decrease in due from banks - time	695	1,087	292
Purchases of premises and equipment, net	(33,086)	(35,268)	(47,861)
Proceeds from sale of premises and equipment	0	0	5,621
Proceeds from sale of foreclosed assets and other real estate owned	2,071	4,754	21,983
Proceeds from sale of available-for-sale securities	247,948	0	342,577
Proceeds from maturities of available-for-sale securities	302,802	1,137,923	1,001,669
Purchases of available-for-sale securities	(7,518)	(261,375)	(5,266,148)
Proceeds from maturities of held-to-maturity securities	85,192	86,229	15,712
Purchases of held-to-maturity securities	(68,368)	(331,273)	(708,580)
Proceeds from bank owned life insurance death benefits	3,686	1,873	3,814
Purchases of bank owned life insurance	0	0	(160,000)
Cash received in business combinations, net	0	276,396	25,425
Disposition of assets and liabilities held for sale	0	0	(134,166)
Net cash used in investing activities	(183,593)	(946,233)	(2,537,736)
FINANCING ACTIVITIES
Net change in deposits	(302,747)	462,530	847,494
Repayments of subordinated debentures	0	(56,189)	(1,563)
Dividends paid on preferred stock	0	0	(47)
Dividends paid on common stock	(100,962)	(94,096)	(78,845)
Net change in other borrowed funds	113,070	(516,726)	(80,254)
Net change in federal funds purchased and securities sold under agreements to repurchase	(92,434)	(25,000)	(116,562)
Net shares (cancelled) issued under stock compensation plans	(2,854)	(5,033)	290
Shares issued under employee stock purchase plan	833	1,151	1,170
Repurchase of common stock	(40,322)	(111,133)	(132,459)
Retirement of preferred stock	0	0	(767)
Net cash (used in) provided by financing activities	(425,416)	(344,496)	438,457
DECREASE IN CASH AND CASH EQUIVALENTS	(68,030)	(968,531)	(1,821,499)
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	682,122	1,650,653	3,472,152
CASH AND CASH EQUIVALENTS, END OF YEAR	$ 614,092	$ 682,122	$ 1,650,653