Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
OPERATING ACTIVITIES:
Net income		$ 540,590	$ 353,885	$ 422,712
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses		(66,326)	137,190	50,438
Provision for depreciation and amortization		44,866	43,769	41,145
Amortization of investment security premiums, net		66,934	59,863	27,631
Deferred income tax (benefit) expense		25,613	(19,540)	14,195
Investment securities (gains) losses, net	[1]	(30,059)	(11,032)	(3,626)
Net gains on sales of loans held for sale		(22,641)	(16,406)	(10,127)
Proceeds from sales of loans held for sale		576,864	297,267	259,153
Origination Of Loans Held For Sale		(524,597)	(313,329)	(244,976)
Net (increase) decrease in trading securities		(29,885)	(770)	3,863
Stock-based compensation		15,415	14,915	13,854
(Increase) decrease in interest receivable		19,788	(13,399)	3,316
Increase (decrease) in interest payable		(3,179)	(9,444)	5,586
Increase (decrease) in income taxes payable		(5,175)	12,345	14,465
Gain on sale of Corporate Trust business		0	0	(11,472)
Proceeds From the Termination of Interest Rate Floors		0	156,740	0
Other changes, net		(10,486)	(68,062)	(73,363)
Net cash provided by (used in) operating activities		597,722	623,992	512,794
INVESTING ACTIVITIES
Proceeds from Equity Method Investment, Distribution, Return of Capital		13,540	0	0
Proceeds from sales of available for sale securities	[1]	80,811	602,477	413,203
Proceeds from maturities/pay downs of available for sale securities	[1]	3,459,106	2,673,510	1,558,244
Purchases of available for sale securities	[1]	(5,947,891)	(6,991,460)	(1,863,180)
Net (increase) decrease in loans		1,134,533	(1,643,775)	(647,890)
Repayments of long-term securities purchased under agreements to resell		(900,000)	0	(150,000)
Proceeds from Securities Purchased under Agreements to Resell		125,000	0	0
Purchases of land, buildings and equipment		(56,716)	(33,134)	(42,575)
Sales of land, buildings and equipment		8,859	1,878	2,033
Net cash provided by (used in) investing activities		(2,082,758)	(5,390,504)	(730,165)
FINANCING ACTIVITIES
Net increase (decrease) in non-interest bearing, savings, interest checking and money market deposits		3,291,466	6,316,100	85,438
Net increase (decrease) in time open and C.D.’s		(402,077)	(163,321)	349,890
Net increase (decrease) in short-term federal funds purchased and securities sold under agreements to repurchase		924,584	247,611	(105,617)
Net Increase (Decrease) in Short-Term Borrowings		11,758	(1,616)	(6,394)
Payments for Repurchase of Redeemable Preferred Stock		0	(150,000)	0
Purchases of treasury stock		(129,361)	(54,163)	(134,904)
Accelerated stock repurchase agreement		0	0	(150,000)
Issuance of stock under equity compensation plans		(15)	(11)	(8)
Cash dividends paid on common stock		(122,693)	(120,818)	(113,466)
Cash dividends paid on preferred stock		0	(6,750)	(9,000)
Net cash provided by (used in) financing activities		3,573,662	6,067,032	(84,061)
Increase (decrease) in cash and cash equivalents		2,088,626	1,300,520	(301,432)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Beginning of Year		2,208,328	907,808	1,209,240
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, End of Year		4,296,954	2,208,328	907,808
Supplemental Cash Flow Information:
Income tax payments, net		119,665	90,066	76,168
Interest paid on deposits and borrowings		16,045	52,245	97,806
Loans transferred to foreclosed real estate		$ 182	$ 93	$ 581

[1] Available for sale debt securities, equity securities, and other securities.