Estimated Fair Values (Assets And Liabilities Carried At Fair Value On A Nonrecurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate remeasured during current year	$ 46,236	$ 48,030	$ 46,633	$ 51,097
Mortgage servicing rights	20,665	20,647
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	120,783	105,994
Other real estate remeasured during current year	20,079	35,344
Fair Value, Measurements, Nonrecurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1 Inputs)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Other real estate remeasured during current year	0	0
Fair Value, Measurements, Nonrecurring | Quoted Prices for Similar Assets and Liabilities (Level 2 Inputs)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Other real estate remeasured during current year	0	0
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3 Inputs)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	120,783	105,994
Other real estate remeasured during current year	$ 20,079	$ 35,344