Loans and Leases (Loans Acquired By Loan Class) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	$ 762,998	$ 809,169	$ 950,516
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	396,938	499,970
Commercial | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	13,654	20,766
Commercial | Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	358,103	453,013
Commercial | Other commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	17,124	12,645
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	6,374	11,844
Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	1,683	1,702
Noncommercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	366,060	309,199
Noncommercial | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI Loans	$ 2,190	$ 1,772