Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 126,467	$ 123,478
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	8,565	7,177
Provision for credit losses	6,020	(22,527)
Gain on other real estate and foreclosed assets	(20)	(3,014)
Loss on sale of securities		87
Deferred tax (benefit) expense	(801)	10,099
Increase in cash surrender value of life insurance contracts	(2,995)	(634)
Loss on disposal of assets	30
Net decrease in loans held for sale	3,028	27,250
Net amortization of securities premium/discount	5,103	11,356
Amortization of intangible assets	3,114	3,748
Stock-based compensation expense	5,726	5,292
Net change in derivative collateral liability	76,152	15,828
Net (decrease) increase in interest payable and other liabilities	(28,313)	18,512
(Increase) decrease in other assets	(112,916)	91,643
Other, net	(3,272)	(7,761)
Net cash provided by operating activities	85,888	280,534
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of available for sale securities		73,219
Proceeds from maturities of securities available for sale	77,339	167,949
Purchases of securities available for sale		(228,454)
Proceeds from maturities of securities held to maturity	30,900	28,125
Purchases of securities held to maturity	(6,023)	(391,761)
Proceeds received upon termination of fair value hedge instruments	16,550
Net (increase) decrease in short-term investments	(1,964,089)	697,625
Net purchases of Federal Home Loan Bank stock	(68,057)
Proceeds from sales of loans and leases	11,006	18,890
Net increase in loans	(306,873)	(227,948)
Purchase of life insurance contracts		(60,000)
Purchases of property and equipment	(5,498)	(11,353)
Proceeds from sales of other real estate and foreclosed assets	235	6,227
Other, net	(4,252)	3,002
Net cash provided by (used in) investing activities	(2,218,762)	75,521
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposits	542,721	33,812
Net increase (decrease) in short-term borrowings	1,648,226	(44,759)
Repayments of long-term debt		(79)
Dividends paid	(26,173)	(23,804)
Payroll tax remitted on net share settlement of equity awards	(2,922)	(1,396)
Proceeds from dividend reinvestment and stock purchase plans	935	881
Repurchase of common stock		(18,490)
Net cash provided by (used in) financing activities	2,162,787	(53,835)
NET INCREASE IN CASH AND DUE FROM BANKS	29,913	302,220
CASH AND DUE FROM BANKS, BEGINNING	564,459	401,201
CASH AND DUE FROM BANKS, ENDING	594,372	703,421
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 202	$ 118