Loans And Allowance For Credit Losses (Summary of Activity in the Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for Credit Loss, Beginning Balance	$ 159,317	$ 134,710	$ 150,136	$ 150,044
Provision for credit losses on loans	5,864	7,287	21,812	(3,399)
Loans charged off	8,838	6,740	17,886	14,202
Recoveries on Loans	2,342	2,782	4,623	5,596
Net loan charge-offs (recoveries)	6,496	3,958	13,263	8,606
Allowance for Credit Loss, Ending Balance	158,685	138,039	158,685	138,039
Liability for Unfunded Lending Commitments, Beginning Balance	28,628	25,032	33,120	24,204
Provision for credit losses on unfunded lending commitments	607	(125)	(3,885)	703
Liability for Unfunded Lending Commitments, Ending Balance	29,235	24,907	29,235	24,907
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LIABILITY FOR UNFUNDED LENDING COMMITMENTS	187,920	162,946	187,920	162,946
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for Credit Loss, Beginning Balance	108,615	94,827	103,293	97,776
Provision for credit losses on loans	(546)	4,716	5,002	1,837
Loans charged off	307	207	599	384
Recoveries on Loans	262	189	328	296
Net loan charge-offs (recoveries)	45	18	271	88
Allowance for Credit Loss, Ending Balance	108,024	99,525	108,024	99,525
Liability for Unfunded Lending Commitments, Beginning Balance	27,105	23,780	31,743	23,271
Provision for credit losses on unfunded lending commitments	737	(163)	(3,901)	346
Liability for Unfunded Lending Commitments, Ending Balance	27,842	23,617	27,842	23,617
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LIABILITY FOR UNFUNDED LENDING COMMITMENTS	135,866	123,142	135,866	123,142
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for Credit Loss, Beginning Balance	50,702	39,883	46,843	52,268
Provision for credit losses on loans	6,410	2,571	16,810	(5,236)
Loans charged off	8,531	6,533	17,287	13,818
Recoveries on Loans	2,080	2,593	4,295	5,300
Net loan charge-offs (recoveries)	6,451	3,940	12,992	8,518
Allowance for Credit Loss, Ending Balance	50,661	38,514	50,661	38,514
Liability for Unfunded Lending Commitments, Beginning Balance	1,523	1,252	1,377	933
Provision for credit losses on unfunded lending commitments	(130)	38	16	357
Liability for Unfunded Lending Commitments, Ending Balance	1,393	1,290	1,393	1,290
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LIABILITY FOR UNFUNDED LENDING COMMITMENTS	$ 52,054	$ 39,804	$ 52,054	$ 39,804