Fair Value Measurement (Fair Value Assets And Liabilities Measured On Nonrecurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	$ 4,827,646	$ 4,139,131
Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	64,238	65,680
Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	4,649,316	3,952,400
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	114,092	121,051
Fair Value, Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	5,835	8,231
Fair Value, Nonrecurring | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	0	0
Fair Value, Nonrecurring | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	0	0
Fair Value, Nonrecurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	5,835	8,231
Fair Value, Nonrecurring | Loans and leases
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	5,835	8,231
Fair Value, Nonrecurring | Loans and leases | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	0	0
Fair Value, Nonrecurring | Loans and leases | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	0	0
Fair Value, Nonrecurring | Loans and leases | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets measured at fair value	$ 5,835	$ 8,231