Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 380,302	$ 325,472
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23,210	21,743
Provision for credit losses	(30,886)	(49,095)
Gain on other real estate and foreclosed assets	(5,210)	(1,124)
Loss (gain) on sale of securities	87	(333)
Deferred tax expense	9,396	1,378
(Increase) decrease in cash surrender value of life insurance contracts	(2,372)	(21,122)
Impairment of or loss on disposal of assets	140	15,165
Loss on extinguishment of debt		4,165
Net decrease in loans held for sale	54,010	43,867
Net amortization of securities premium/discount	29,475	38,318
Amortization of intangible assets	10,762	12,746
Stock-based compensation expense	17,507	17,270
Net change in derivative collateral liability	36,776	53,387
Increase in interest payable and other liabilities	1,964	22,037
Decrease in other assets	174,915	60,971
Other, net	(24,999)	(13,970)
Net cash provided by operating activities	675,077	530,875
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of available for sale securities	73,219	198,681
Proceeds from maturities of securities available for sale	415,221	831,433
Purchases of securities available for sale	(517,178)	(2,235,723)
Proceeds from maturities of securities held to maturity	111,612	99,044
Purchases of securities held to maturity	(859,333)	(59,362)
Proceeds received upon termination of fair value hedge instruments	74,006
Net (increase) decrease in short-term investments	3,568,970	(1,728,995)
Net redemptions of Federal Home Loan Bank stock	4,969	52,535
Proceeds from sales of loans and leases	26,619	12,540
Net (increase) decrease in loans	(1,545,537)	915,652
Purchase of life insurance contracts	(65,000)	(75,000)
Proceeds from the surrender of life insurance contracts		44,045
Purchases of property and equipment	(22,352)	(12,402)
Proceeds from sales of other real estate and foreclosed assets	11,308	7,804
Other, net	2,778	35,903
Net cash provided by (used in) investing activities	1,279,302	(1,913,845)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in deposits	(1,514,623)	1,510,280
Net increase (decrease) in short-term borrowings	(122,080)	77,715
Proceeds from the issuance of long-term debt		22,388
Repayments of long-term debt	(480)	(153,365)
Dividends paid	(70,926)	(72,046)
Payroll tax remitted on net share settlement of equity awards	(1,891)	(1,298)
Proceeds from exercise of stock options	227	439
Proceeds from dividend reinvestment and stock purchase plans	2,671	2,940
Repurchase of common stock	(58,892)	(2,509)
Net cash provided by (used in) financing activities	(1,765,994)	1,384,544
NET INCREASE IN CASH AND DUE FROM BANKS	188,385	1,574
CASH AND DUE FROM BANKS, BEGINNING	401,201	526,306
CASH AND DUE FROM BANKS, ENDING	589,586	527,880
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 328	$ 2,623