Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities:
Net income	$ 305,392,000	$ 194,820,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit loss	27,879,000	13,741,000
Specific reserve, other real estate owned	2,510,000	416,000
Depreciation of bank premises and equipment	16,362,000	16,355,000
Gain on sale of bank premises and equipment	(198,000)	(3,426,000)
Gain on sale of other real estate owned	(6,833,000)	(1,781,000)
Accretion of investment securities discounts	(1,431,000)	(1,257,000)
Amortization of investment securities premiums	5,244,000	11,617,000
Investment securities transactions, net	3,000
Unrealized loss on equity securities with readily determinable fair values	200,000	728,000
Stock based compensation expense	255,000	347,000
Earnings from affiliates and other investments	(367,000)	(9,960,000)
Deferred tax expense (benefit)	4,747,000	(1,838,000)
Increase in accrued interest receivable	(11,872,000)	(6,483,000)
Increase in other assets	(38,158,000)	(7,325,000)
Increase in other liabilities	37,927,000	82,553,000
Net cash provided by operating activities	341,660,000	288,507,000
Investing activities:
Proceeds from maturities of securities	51,167,000	2,200,000
Proceeds from sales and calls of available for sale securities	2,045,000	800,000
Purchases of available for sale securities	(980,571,000)	(1,160,632,000)
Principal collected on mortgage backed securities	474,282,000	605,706,000
Net (increase) decrease in loans	(471,695,000)	153,278,000
Purchases of other investments	(25,431,000)	(72,799,000)
Distributions from other investments	8,773,000	5,995,000
Purchases of bank premises and equipment	(19,079,000)	(12,798,000)
Proceeds from sales of bank premises and equipment	269,000	12,523,000
Proceeds from sales of other real estate owned	7,777,000	8,427,000
Net cash used in investing activities	(952,463,000)	(457,300,000)
Financing activities:
Net (decrease) increase in non-interest bearing demand deposits	(629,637,000)	162,603,000
Net (decrease) increase in savings and interest bearing demand deposits	(388,433,000)	158,665,000
Net increase (decrease) in time deposits	274,672,000	(58,630,000)
Net increase in securities sold under repurchase agreements	73,090,000	67,471,000
Net decrease in other borrowed funds	(148,000)	(145,000)
Redemption of long-term debt	(25,774,000)
Purchase of treasury stock	(4,487,000)	(51,939,000)
Proceeds from stock transactions	654,000	732,000
Payments of cash dividends	(78,247,000)	(75,375,000)
Net cash (used in) provided by financing activities	(778,310,000)	203,382,000
(Decrease) increase in cash and cash equivalents	(1,389,113,000)	34,589,000
Cash and cash equivalents at beginning of period	2,087,724,000	3,209,242,000
Cash and cash equivalents at end of period	698,611,000	3,243,831,000
Supplemental cash flow information:
Interest paid	77,834,000	21,604,000
Income taxes paid	69,799,000	1,980,000
Non-cash investing and financing activities:
Net transfers from loans to other real estate owned	$ 554,000	204,000
Net transfers from bank premises and equipment to other assets		$ 2,476,000