Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Activities:
Net income (loss)	$ 582,542	$ 597,973	$ 579,150
Adjustments to reconcile net income to net cash from operating activities:
Credit loss expense	64,985	46,171	3,000
Deferred tax expense (benefit)	(11,600)	(14,829)	(4,918)
Accretion of loan discounts	(23,951)	(17,724)	(12,921)
Securities premium amortization (discount accretion), net	45,213	63,893	97,400
Net (gain) loss on securities transactions	96	(66)	0
Depreciation and amortization	82,817	76,442	71,344
Net (gain) loss on sale/exchange/write-down of assets/foreclosed assets	(141)	750	109
Stock-based compensation	19,763	24,590	18,322
Net tax benefit from stock-based compensation	3,795	894	4,602
Earnings on life insurance policies	(3,745)	(2,944)	(2,096)
Net change in:
Trading account securities	(3,644)	(2,220)	(716)
Lease right-of-use assets	25,264	23,573	24,409
Accrued interest receivable and other assets	259,142	(232,665)	(116,243)
Accrued interest payable and other liabilities	(51,004)	(84,993)	61,140
Net cash provided by (used in) operating activities	989,532	478,845	722,582
Investing Activities:
Securities held to maturity: Purchases	0	(1,147,624)	(1,424,105)
Securities held to maturity: Maturities, calls and principal repayments	81,750	162,142	561,388
Securities available for sale:
Purchases	(17,899,779)	(19,124,336)	(22,178,248)
Sales	123,254	1,904,067	0
Maturities, calls and principal repayments	19,600,708	19,103,872	15,683,097
Proceeds from sale of loans	3,323	15,851	2,365
Net change in loans	(1,966,111)	(1,701,895)	(824,021)
Net cash paid in insurance agency asset acquisitions	(703)	0	0
Benefits received on life insurance policies	1,823	1,937	2,047
Proceeds from sales of premises and equipment	25	1,282	63
Purchases of premises and equipment	(127,776)	(158,630)	(102,501)
Proceeds from sales of repossessed properties	2,607	583	2,585
Net cash provided by (used in) investing activities	(180,879)	(942,751)	(8,277,330)
Financing Activities:
Net change in deposits	802,180	(2,033,628)	1,258,500
Net change in short-term borrowings	223,528	(570,903)	1,945,567
Proceeds from stock option exercises	22,643	9,299	16,659
Purchase of treasury stock	(60,901)	(42,720)	(4,391)
Cash dividends paid on preferred stock	(6,675)	(6,675)	(6,675)
Cash dividends paid on common stock	(242,446)	(232,323)	(209,780)
Net cash provided by (used in) financing activities	738,329	(2,876,950)	2,999,880
Net change in cash and cash equivalents	1,546,982	(3,340,856)	(4,554,868)
Cash and cash equivalents at beginning of year	8,687,276	12,028,132	16,583,000
Cash and cash equivalents at end of year	$ 10,234,258	$ 8,687,276	$ 12,028,132