Loans And Allowance For Credit Losses (Summary of Activity in the Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for Credit Loss, Beginning Balance	$ 158,557	$ 158,685	$ 162,395	$ 150,136	$ 150,136
Provision for credit losses on loans	11,861	13,343	26,657	35,155
Loans charged off	11,757	11,926	34,790	29,812
Recoveries on Loans	2,178	2,142	6,577	6,765
Net loan charge-offs (recoveries)	9,579	9,784	28,213	23,047
Allowance for Credit Loss, Ending Balance	160,839	162,244	160,839	162,244	162,395
Liability for Unfunded Lending Commitments, Beginning Balance	20,705	29,235	25,246	33,120	33,120
Provision for credit losses on unfunded lending commitments	(2,721)	(1,698)	(7,262)	(5,583)
Liability for Unfunded Lending Commitments, Ending Balance	17,984	27,537	17,984	27,537	25,246
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LIABILITY FOR UNFUNDED LENDING COMMITMENTS	178,823	189,781	178,823	189,781
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for Credit Loss, Beginning Balance	107,217	108,024	108,201	103,293	103,293
Provision for credit losses on loans	(63)	5,201	(551)	10,203
Loans charged off	362	2,664	1,528	3,263	3,885
Recoveries on Loans	255	66	925	394
Net loan charge-offs (recoveries)	107	2,598	603	2,869
Allowance for Credit Loss, Ending Balance	107,047	110,627	107,047	110,627	108,201
Liability for Unfunded Lending Commitments, Beginning Balance	19,363	27,842	23,909	31,743	31,743
Provision for credit losses on unfunded lending commitments	(2,715)	(1,724)	(7,261)	(5,625)
Liability for Unfunded Lending Commitments, Ending Balance	16,648	26,118	16,648	26,118	23,909
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LIABILITY FOR UNFUNDED LENDING COMMITMENTS	123,695	136,745	123,695	136,745
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for Credit Loss, Beginning Balance	51,340	50,661	54,194	46,843	46,843
Provision for credit losses on loans	11,924	8,142	27,208	24,952
Loans charged off	11,395	9,262	33,262	26,549	36,283
Recoveries on Loans	1,923	2,076	5,652	6,371
Net loan charge-offs (recoveries)	9,472	7,186	27,610	20,178
Allowance for Credit Loss, Ending Balance	53,792	51,617	53,792	51,617	54,194
Liability for Unfunded Lending Commitments, Beginning Balance	1,342	1,393	1,337	1,377	1,377
Provision for credit losses on unfunded lending commitments	(6)	26	(1)	42
Liability for Unfunded Lending Commitments, Ending Balance	1,336	1,419	1,336	1,419	$ 1,337
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LIABILITY FOR UNFUNDED LENDING COMMITMENTS	$ 55,128	$ 53,036	$ 55,128	$ 53,036