Loans and Leases (Narrative) (Detail) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) loan	Jun. 30, 2019 USD ($) loan
Operating Leased Assets [Line Items]
Total operating lease liability payments	$ 197,943		$ 197,943
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	3,800	$ 3,400	6,800	$ 6,100
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	1,900	4,200	$ 3,100	$ 5,600
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan			0	0
Commercial Portfolio Segment [Member] \| Equipment financing
Operating Leased Assets [Line Items]
Net Investment in Direct Financing and Sales Type Leases	226,800		$ 226,800
Total operating lease liability payments	246,000		246,000
Sales-type and Direct Financing Leases, Interest Income	$ 1,800	$ 1,500	$ 3,400	$ 2,900

Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

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-Name Accounting Standards Codification
-Topic 310
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-Section 50
-Paragraph 34
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Amount of lessee's undiscounted obligation for lease payment for operating lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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