Loans and Leases (Summary Of The Recorded Investment Of Company's TDRs) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDR	$ 163,344	$ 235,427
Specific reserves for TDR included in the balance of ALLL	301,187	359,431	$ 209,096	$ 212,353
Additional funds committed to borrowers in TDR status	5,975	12,895
Commercial Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Specific reserves for TDR included in the balance of ALLL	257,877	312,244	161,669	164,073
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	3,000	17,600	20,300
Consumer Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Specific reserves for TDR included in the balance of ALLL	43,310	47,187	47,427	$ 48,280
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	400	800	$ 1,500
Performing Financial Instruments [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDR	110,625	140,089
Nonperforming Financial Instruments [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDR	52,719	95,338
Troubled Debt Restructures [Member] | Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Specific reserves for TDR included in the balance of ALLL	9,017	8,657
Troubled Debt Restructures [Member] | Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Specific reserves for TDR included in the balance of ALLL	$ 3,745	$ 4,071