Fair Value Of Financial Instruments (Schedule Of Estimated Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands		Jun. 30, 2024	Dec. 31, 2023
Carrying Amount
Fair Value, Balance Sheet Grouping [Line Items]
Loans		$ 17,163,065	$ 17,205,479
Loans held for sale		2,930	4,177
Investment securities		8,851,372	9,941,786
Federal Funds Sold		0	5,025
Securities purchased under agreements to resell		475,000	450,000
Interest earning deposits with banks		2,215,057	2,239,010
Cash and due from banks		329,692	443,147
Derivative Asset		86,709	116,876
Assets held in trust for deferred compensation plan		21,550	20,538
Assets, Fair Value Financial Instruments		29,145,375	30,426,038
Non-interest bearing deposits		7,492,751	7,975,935
Savings, interest checking and money market deposits		14,367,710	14,512,273
Certificates of deposits		2,418,799	2,875,690
Federal funds purchased		254,720	261,305
Securities sold under agreements to repurchase		2,296,679	2,647,510
Other borrowings		3,956	1,366
Derivative Liabilities		36,915	37,899
Liabilities held in trust for deferred compensation plan		21,550	20,538
Financial Liabilities Fair Value Disclosure		26,893,080	28,332,516
Carrying Amount | Business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		6,090,724	6,019,036
Carrying Amount | Real estate - construction and land
Fair Value, Balance Sheet Grouping [Line Items]
Loans		1,396,515	1,446,764
Carrying Amount | Real estate - business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		3,572,539	3,719,306
Carrying Amount | Real estate - personal
Fair Value, Balance Sheet Grouping [Line Items]
Loans		3,055,182	3,026,041
Carrying Amount | Consumer
Fair Value, Balance Sheet Grouping [Line Items]
Loans		2,145,609	2,077,723
Carrying Amount | Revolving home equity
Fair Value, Balance Sheet Grouping [Line Items]
Loans		331,381	319,894
Carrying Amount | Consumer credit card
Fair Value, Balance Sheet Grouping [Line Items]
Loans		566,925	589,913
Carrying Amount | Overdrafts
Fair Value, Balance Sheet Grouping [Line Items]
Loans		4,190	6,802
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping [Line Items]
Loans		16,309,986	16,347,391
Loans held for sale		2,930	4,177
Investment securities		8,851,372	9,941,786
Federal Funds Sold		0	5,025
Securities purchased under agreements to resell		471,259	444,448
Interest earning deposits with banks		2,215,057	2,239,010
Cash and due from banks		329,692	443,147
Derivative Asset		86,709	116,876
Assets held in trust for deferred compensation plan		21,550	20,538
Assets, Fair Value Financial Instruments		28,288,555	29,562,398
Non-interest bearing deposits		7,492,751	7,975,935
Savings, interest checking and money market deposits		14,367,710	14,512,273
Certificates of deposits		2,454,596	2,916,627
Federal funds purchased		254,720	261,305
Securities sold under agreements to repurchase		2,299,857	2,650,951
Other borrowings		3,956	1,366
Derivative Liabilities		36,915	37,899
Liabilities held in trust for deferred compensation plan		21,550	20,538
Financial Liabilities Fair Value Disclosure		26,932,055	28,376,894
Estimate of Fair Value Measurement [Member] | Business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		5,949,560	5,873,549
Estimate of Fair Value Measurement [Member] | Real estate - construction and land
Fair Value, Balance Sheet Grouping [Line Items]
Loans		1,369,734	1,420,522
Estimate of Fair Value Measurement [Member] | Real estate - business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		3,449,075	3,594,834
Estimate of Fair Value Measurement [Member] | Real estate - personal
Fair Value, Balance Sheet Grouping [Line Items]
Loans		2,588,478	2,568,026
Estimate of Fair Value Measurement [Member] | Consumer
Fair Value, Balance Sheet Grouping [Line Items]
Loans		2,096,790	2,016,334
Estimate of Fair Value Measurement [Member] | Revolving home equity
Fair Value, Balance Sheet Grouping [Line Items]
Loans		328,442	317,013
Estimate of Fair Value Measurement [Member] | Consumer credit card
Fair Value, Balance Sheet Grouping [Line Items]
Loans		523,830	550,464
Estimate of Fair Value Measurement [Member] | Overdrafts
Fair Value, Balance Sheet Grouping [Line Items]
Loans		4,077	6,649
Estimate of Fair Value Measurement [Member] | Level 1
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Loans held for sale		0	0
Investment securities		1,685,631	822,237
Federal Funds Sold		0	5,025
Securities purchased under agreements to resell		0	0
Interest earning deposits with banks		2,215,057	2,239,010
Cash and due from banks		329,692	443,147
Derivative Asset		0	0
Assets held in trust for deferred compensation plan		21,550	20,538
Assets, Fair Value Financial Instruments		4,251,930	3,529,957
Non-interest bearing deposits		7,492,751	7,975,935
Savings, interest checking and money market deposits		14,367,710	14,512,273
Certificates of deposits		0	0
Federal funds purchased		254,720	261,305
Securities sold under agreements to repurchase		0	0
Other borrowings		0	0
Derivative Liabilities		0	0
Liabilities held in trust for deferred compensation plan		21,550	20,538
Financial Liabilities Fair Value Disclosure		22,136,731	22,770,051
Estimate of Fair Value Measurement [Member] | Level 1 | Business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 1 | Real estate - construction and land
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 1 | Real estate - business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 1 | Real estate - personal
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 1 | Consumer
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 1 | Revolving home equity
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 1 | Consumer credit card
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 1 | Overdrafts
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 2
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Loans held for sale		2,930	4,177
Investment securities		6,940,990	8,896,129
Federal Funds Sold		0	0
Securities purchased under agreements to resell		0	0
Interest earning deposits with banks		0	0
Cash and due from banks		0	0
Derivative Asset		86,511	116,710
Assets held in trust for deferred compensation plan		0	0
Assets, Fair Value Financial Instruments		7,030,431	9,017,016
Non-interest bearing deposits		0	0
Savings, interest checking and money market deposits		0	0
Certificates of deposits		0	0
Federal funds purchased		0	0
Securities sold under agreements to repurchase		0	0
Other borrowings		3,956	1,366
Derivative Liabilities		36,832	37,704
Liabilities held in trust for deferred compensation plan		0	0
Financial Liabilities Fair Value Disclosure		40,788	39,070
Estimate of Fair Value Measurement [Member] | Level 2 | Business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 2 | Real estate - construction and land
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 2 | Real estate - business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 2 | Real estate - personal
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 2 | Consumer
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 2 | Revolving home equity
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 2 | Consumer credit card
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Level 2 | Overdrafts
Fair Value, Balance Sheet Grouping [Line Items]
Loans		0	0
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping [Line Items]
Loans		16,309,986	16,347,391
Loans held for sale		0	0
Investment securities		224,751	223,420
Federal Funds Sold		0	0
Securities purchased under agreements to resell		471,259	444,448
Interest earning deposits with banks		0	0
Cash and due from banks		0	0
Derivative Asset		198	166
Assets held in trust for deferred compensation plan		0	0
Assets, Fair Value Financial Instruments		17,006,194	17,015,425
Non-interest bearing deposits		0	0
Savings, interest checking and money market deposits		0	0
Certificates of deposits		2,454,596	2,916,627
Federal funds purchased		0	0
Securities sold under agreements to repurchase		2,299,857	2,650,951
Other borrowings		0	0
Derivative Liabilities		83	195
Liabilities held in trust for deferred compensation plan		0	0
Financial Liabilities Fair Value Disclosure		4,754,536	5,567,773
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) | Business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		5,949,560	5,873,549
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) | Real estate - construction and land
Fair Value, Balance Sheet Grouping [Line Items]
Loans		1,369,734	1,420,522
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) | Real estate - business
Fair Value, Balance Sheet Grouping [Line Items]
Loans		3,449,075	3,594,834
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) | Real estate - personal
Fair Value, Balance Sheet Grouping [Line Items]
Loans		2,588,478	2,568,026
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) | Consumer
Fair Value, Balance Sheet Grouping [Line Items]
Loans		2,096,790	2,016,334
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) | Revolving home equity
Fair Value, Balance Sheet Grouping [Line Items]
Loans		328,442	317,013
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) | Consumer credit card
Fair Value, Balance Sheet Grouping [Line Items]
Loans		523,830	550,464
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) | Overdrafts
Fair Value, Balance Sheet Grouping [Line Items]
Loans		4,077	6,649
Federal Funds Sold		0	5,025
Securities purchased under agreements to resell		475,000	450,000
Interest earning deposits with banks		2,215,057	2,239,010
Cash and due from banks		329,692	443,147
Derivative Asset	[1]	86,709	116,876
Assets held in trust for deferred compensation plan		21,550	20,538
Non-interest bearing deposits		7,492,751	7,975,935
Savings, interest checking and money market deposits		14,367,710	14,512,273
Other borrowings		3,984	1,404
Derivative Liabilities	[1]	36,915	37,899
Liabilities held in trust for deferred compensation plan		21,550	20,538
Level 1
Fair Value, Balance Sheet Grouping [Line Items]
Derivative Asset	[1]	0	0
Assets held in trust for deferred compensation plan		21,550	20,538
Derivative Liabilities	[1]	0	0
Liabilities held in trust for deferred compensation plan		21,550	20,538
Level 2
Fair Value, Balance Sheet Grouping [Line Items]
Derivative Asset	[1]	86,511	116,710
Assets held in trust for deferred compensation plan		0	0
Derivative Liabilities	[1]	36,832	37,704
Liabilities held in trust for deferred compensation plan		0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping [Line Items]
Derivative Asset	[1]	198	166
Assets held in trust for deferred compensation plan		0	0
Derivative Liabilities	[1]	83	195
Liabilities held in trust for deferred compensation plan		$ 0	$ 0

[1] * The fair value of each class of derivative is shown in Note 11.