Fair Value Measurement (Fair Value Assets And Liabilities Measured On Nonrecurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	$ 3,410,141	$ 3,522,949
Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	62,306	63,952
Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	3,167,638	3,301,094
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	180,197	157,903
Fair Value, Measurements, Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	70,741	75,189
Fair Value, Measurements, Nonrecurring | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	0	0
Fair Value, Measurements, Nonrecurring | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	0	0
Fair Value, Measurements, Nonrecurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	70,741	75,189
Fair Value, Measurements, Nonrecurring | Loans and leases
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	70,741	75,121
Fair Value, Measurements, Nonrecurring | Loans and leases | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	0	0
Fair Value, Measurements, Nonrecurring | Loans and leases | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	0	0
Fair Value, Measurements, Nonrecurring | Loans and leases | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring	$ 70,741	75,121
Fair Value, Measurements, Nonrecurring | Other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring		68
Fair Value, Measurements, Nonrecurring | Other real estate owned | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring		0
Fair Value, Measurements, Nonrecurring | Other real estate owned | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring		0
Fair Value, Measurements, Nonrecurring | Other real estate owned | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, nonrecurring		$ 68