Loans and Leases (Interest Income From Impaired Loans And Leases, By Class) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 344,193	$ 263,812	$ 306,344	$ 256,289
Accrued Interest Income	2,134	2,104	4,571	4,274
Cash Basis Interest Income	643	523	2,103	1,067
Commercial Portfolio Segment [Member] \| Commercial non-mortgage
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	136,483	106,753	115,903	98,511
Accrued Interest Income	875	844	1,928	1,764
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	138	201	139	204
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	26,017	13,070	25,411	12,354
Accrued Interest Income	169	61	315	134
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	8,373	4,451	6,613	5,132
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	121,488	101,245	113,806	101,850
Accrued Interest Income	781	912	1,611	1,820
Cash Basis Interest Income	230	282	860	546
Consumer Portfolio Segment [Member] \| Home equity
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	50,573	38,092	43,863	38,238
Accrued Interest Income	309	287	700	556
Cash Basis Interest Income	413	241	1,243	521
Consumer Portfolio Segment [Member] \| Consumer Loan
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	1,121	0	609	0
Accrued Interest Income	0	0	17	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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