Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating Activities:
Net income (loss)	$ 648,557	$ 582,542	$ 597,973
Adjustments to reconcile net income to net cash from operating activities:
Credit loss expense	44,202	64,985	46,171
Deferred tax expense (benefit)	5,372	(11,600)	(14,829)
Accretion of loan discounts	(26,624)	(23,951)	(17,724)
Securities premium amortization (discount accretion), net	39,600	45,213	63,893
Net (gain) loss on securities transactions	850	96	(66)
Depreciation and amortization	87,785	82,817	76,442
Net (gain) loss on sale/exchange/write-down of assets/foreclosed assets	(3,031)	(141)	750
Stock-based compensation	24,755	19,763	24,590
Net tax benefit from stock-based compensation	2,265	3,795	894
Earnings on life insurance policies	(3,940)	(3,745)	(2,944)
Net change in:
Trading account securities	(3,694)	(3,644)	(2,220)
Lease right-of-use assets	24,832	25,264	23,573
Accrued interest receivable and other assets	(7,669)	259,142	(232,665)
Accrued interest payable and other liabilities	(559,281)	(51,004)	(84,993)
Net cash provided by (used in) operating activities	273,979	989,532	478,845
Investing Activities:
Securities held to maturity: Purchases	(1,500)	0	(1,147,624)
Securities held to maturity: Maturities, calls and principal repayments	100,314	81,750	162,142
Securities available for sale:
Purchases	(21,495,449)	(17,899,779)	(19,124,336)
Sales	45,372	123,254	1,904,067
Maturities, calls and principal repayments	21,021,849	19,600,708	19,103,872
Proceeds from sale of loans	14,119	3,323	15,851
Net change in loans	(1,158,427)	(1,966,111)	(1,701,895)
Net cash paid in insurance agency asset acquisitions	0	(703)	0
Benefits received on life insurance policies	2,479	1,823	1,937
Proceeds from sales of premises and equipment	960	25	1,282
Purchases of premises and equipment	(146,652)	(127,776)	(158,630)
Proceeds from sales of repossessed properties	15,840	2,607	583
Net cash provided by (used in) investing activities	(1,601,095)	(180,879)	(942,751)
Financing Activities:
Net change in deposits	195,116	802,180	(2,033,628)
Net change in short-term borrowings	179,714	223,528	(570,903)
Proceeds from stock option exercises	11,946	22,643	9,299
Purchase of treasury stock	(157,832)	(60,901)	(42,720)
Cash dividends paid on preferred stock	(6,675)	(6,675)	(6,675)
Cash dividends paid on common stock	(255,356)	(242,446)	(232,323)
Net cash provided by (used in) financing activities	(33,087)	738,329	(2,876,950)
Net change in cash and cash equivalents	(1,360,203)	1,546,982	(3,340,856)
Cash and cash equivalents at beginning of year	10,234,258	8,687,276	12,028,132
Cash and cash equivalents at end of year	$ 8,874,055	$ 10,234,258	$ 8,687,276