Loans and Leases (Interest Income From Impaired Loans And Leases, By Class) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 315,533	$ 261,939	$ 282,161	$ 264,982
Accrued Interest Income	2,202	1,920	6,773	6,194
Cash Basis Interest Income	586	517	2,689	1,584
Commercial Portfolio Segment [Member] \| Commercial non-mortgage
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	127,676	102,996	114,027	103,772
Accrued Interest Income	954	751	2,882	2,515
Cash Basis Interest Income	0	0	0	0
Commercial Portfolio Segment [Member] \| Asset-based
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	1,949	4,673	1,950	4,694
Accrued Interest Income	0	0	0	0
Cash Basis Interest Income	0	0	0	0
Commercial Portfolio Segment [Member] \| Commercial real estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	24,555	15,051	22,440	13,526
Accrued Interest Income	192	60	507	194
Cash Basis Interest Income	0	0	0	0
Commercial Portfolio Segment [Member] \| Equipment financing
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	7,488	4,718	6,308	5,901
Accrued Interest Income	0	0	0	0
Cash Basis Interest Income	0	0	0	0
Consumer Portfolio Segment [Member] \| Residential
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	103,608	97,917	95,270	99,599
Accrued Interest Income	741	862	2,352	2,682
Cash Basis Interest Income	289	271	1,149	817
Consumer Portfolio Segment [Member] \| Home equity
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	49,309	36,584	41,826	37,490
Accrued Interest Income	302	247	1,002	803
Cash Basis Interest Income	297	246	1,540	767
Consumer Portfolio Segment [Member] \| Consumer Loan
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	948	0	340	0
Accrued Interest Income	13	0	30	0
Cash Basis Interest Income	$ 0	$ 0	$ 0	$ 0

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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