Loans and Leases (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Liability, Payments, Due	$ 208,950		$ 208,950
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	3,400	$ 2,400	6,100	$ 4,300
Write-down of TDR's			(5,600)	$ (5,200)
Finance Leases Portfolio Segment [Member]
Operating Leased Assets [Line Items]
Net Investment in Direct Financing and Sales Type Leases	164,000		164,000
Lessee, Operating Lease, Liability, Payments, Due	178,500		178,500
Sales-type and Direct Financing Leases, Interest Income	$ 1,500		$ 2,900