Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 244,261	$ 244,913
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	17,514	14,814
Provision for credit losses	13,653	(32,288)
Gain on other real estate and foreclosed assets	(324)	(3,276)
Loss on sale of securities		87
Deferred tax expense	8,450	11,634
Increase in cash surrender value of life insurance contracts	(7,466)	(920)
Loss on disposal of assets	651	539
Net (increase) decrease in loans held for sale	(29,454)	43,329
Net amortization of securities premium/discount	9,674	21,311
Amortization of intangible assets	6,071	7,334
Stock-based compensation expense	12,194	11,379
Net change in derivative collateral liability	85,986	96,591
Net increase (decrease) in interest payable and other liabilities	6,547	(19,009)
(Increase) decrease in other assets	(146,238)	108,679
Other, net	(6,828)	(18,286)
Net cash provided by operating activities	214,691	486,831
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of available for sale securities		73,219
Proceeds from maturities of securities available for sale	157,474	295,121
Purchases of securities available for sale		(383,398)
Proceeds from maturities of securities held to maturity	72,365	77,794
Purchases of securities held to maturity	(6,023)	(708,439)
Proceeds received upon termination of fair value hedge instruments	16,550	49,167
Net (increase) decrease in short-term investments	(350,103)	2,959,439
Net (purchases) redemption of Federal Home Loan Bank stock	(68,057)	37,423
Proceeds from sales of loans and leases	27,439	26,619
Net increase in loans	(718,348)	(808,525)
Purchase of life insurance contracts		(65,000)
Purchases of property and equipment	(18,273)	(18,212)
Proceeds from sales of other real estate and foreclosed assets	1,420	9,378
Other, net	(7,594)	4,277
Net cash provided by (used in) investing activities	(893,150)	1,548,863
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in deposits	973,152	(599,465)
Net decrease in short-term borrowings	(241,733)	(1,035,050)
Repayments of long-term debt		(480)
Dividends paid	(52,350)	(47,365)
Payroll tax remitted on net share settlement of equity awards	(3,267)	(1,799)
Proceeds from exercise of stock options		227
Proceeds from dividend reinvestment and stock purchase plans	1,934	1,800
Repurchase of common stock		(56,489)
Net cash provided by (used in) financing activities	677,736	(1,738,621)
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	(723)	297,073
CASH AND DUE FROM BANKS, BEGINNING	564,459	401,201
CASH AND DUE FROM BANKS, ENDING	563,736	698,274
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 1,322	$ 118