Loans and Leases (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Receivables [Abstract]
Loans and leases, deferred fees and costs	$ 71,100	$ 70,400
Discounts on acquired loans	45,400	50,000
Total loans pledged to secure borrowings	13,200,000
Outstanding contractual unpaid principal balance of non-covered purchased impaired loans	170,800	183,700
Direct Financing Lease, Interest Income	8,400
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans acquired with deteriorated credit quality	$ 123,844	$ 134,500	$ 173,492