Loans and Leases (Interest Income From Impaired Loans And Leases, By Class) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 277,661	$ 262,717	$ 259,757	$ 268,442
Accrued Interest Income	1,743	1,954	5,344	6,201
Cash Basis Interest Income	531	542	1,794	1,672
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	118,841	124,993	118,065	128,234
Accrued Interest Income	1,027	1,070	3,133	3,309
Cash Basis Interest Income	285	304	986	918
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	46,753	46,892	45,972	47,317
Accrued Interest Income	341	336	998	1,029
Cash Basis Interest Income	246	238	808	754
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	81,816	58,874	64,932	57,389
Accrued Interest Income	249	352	704	1,299
Cash Basis Interest Income	0	0	0	0
Commercial Portfolio Segment [Member] \| Asset Based Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,279	0	4,279	0
Accrued Interest Income	0	0		0
Cash Basis Interest Income	0	0	0	0
Commercial Real Estate Portfolio Segment [Member] \| Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	20,249	23,930	20,647	26,689
Accrued Interest Income	96	77	329	374
Cash Basis Interest Income	0	0	0	0
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	828	4,386	831	5,171
Accrued Interest Income	0	12	12	81
Cash Basis Interest Income	0	0	0	0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,895	3,642	5,031	3,642
Accrued Interest Income	30	107	168	109
Cash Basis Interest Income	$ 0	$ 0	$ 0	$ 0

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- Definition

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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&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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