Loans and Leases (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Receivables [Abstract]
Loans and leases, deferred fees and costs	$ 72,800	$ 72,800	$ 70,400
Discounts on acquired loans	41,300	41,300	50,000
Total loans pledged to secure borrowings	12,900,000	12,900,000
Outstanding contractual unpaid principal balance of non-covered purchased impaired loans	158,800	158,800	183,700
Direct Financing Lease, Interest Income	8,100	16,500
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans acquired with deteriorated credit quality	$ 113,552	$ 113,552	$ 134,500	$ 157,876