Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
OPERATING ACTIVITIES
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 118,154	$ 283,607
INVESTING ACTIVITIES
Proceeds from sales of securities available for sale	1,689	150
Proceeds from maturities and calls of securities available for sale	184,059	151,477
Purchases of securities available for sale	(7,855)	(1,077,461)
Proceeds from sales of equity securities	98	149
Purchases of equity securities	(246)	(353)
Proceeds from sales and redemptions of other investment securities	21,547	1,295
Purchases of other investment securities	(52,217)	(11,591)
Redemption of bank-owned life insurance policies	0	778
Purchases of bank premises and equipment	(3,447)	(3,509)
Proceeds from sales of bank premises and equipment	2,465	557
Proceeds from the sales of OREO properties	279	1,325
Net change in loans and leases	(54,938)	(366,414)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	91,434	(1,303,597)
FINANCING ACTIVITIES
Cash dividends paid	(48,651)	(46,655)
Acquisition of treasury stock	(1,374)	(26,061)
Proceeds from exercise of stock options	1,559	5,027
Redemption of subordinated debt	(10,250)	0
Repayment of long-term Federal Home Loan Bank borrowings	(1,900,000)	0
Proceeds from issuance of long-term Federal Home Loan Bank borrowings	2,500,000	0
Changes in:
Deposits	(18,227)	125,076
Federal funds purchased, securities sold under agreements to repurchase and other short-term borrowings	9,396	7,526
NET CASH PROVIDED BY FINANCING ACTIVITIES	532,453	64,913
Increase (Decrease) in cash and cash equivalents	742,041	(955,077)
Cash and cash equivalents at beginning of year	1,176,652	3,758,170
Cash and cash equivalents at end of period	1,918,693	2,803,093
Noncash investing activities:
Transfers of loans to OREO	2,919	186
Transfers of loans to bank premises and equipment	0	4,541
Subsidiaries [Member]
Acquisition of subsidiaries and purchase price adjustments:
Assets acquired, net of cash	0	(128)
Liabilities assumed	0	2,622
Goodwill	$ 0	$ 2,750