Fair Value Measurement (Losses Resulting From Nonrecurring Fair Value Adjustments) (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss from nonrecurring measurements	$ 48,634	$ 35,008	$ 31,865
Other Real Estate Owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss from nonrecurring measurements	146	1,719	2,782
Loans And Leases
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss from nonrecurring measurements	$ 48,488	$ 33,289	$ 29,083