Goodwill and Other Intangible Assets (Summary of Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other intangibe assets:
Gross amount	$ 41,904	$ 41,904
Accumulated amortization	37,481	35,818
Carrying Amount	4,423	6,086
Core deposits
Other intangibe assets:
Gross amount	38,294	38,294
Accumulated amortization	34,960	33,297
Carrying Amount	3,334	4,997
Trade name
Other intangibe assets:
Gross amount	1,600	1,600
Accumulated amortization	511	511
Carrying Amount	1,089	1,089
Trust relationship
Other intangibe assets:
Gross amount	1,568	1,568
Accumulated amortization	1,568	1,568
Carrying Amount	0	0
Other intangible
Other intangibe assets:
Gross amount	442	442
Accumulated amortization	442	442
Carrying Amount	$ 0	$ 0