Goodwill and Other Intangible Assets (Core Deposit Intangibles) (Details) - Core Deposit Intangibles - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Impairment write downs on the core deposit intangibles	$ 0	$ 0	$ 0	$ 0
Gross balance	86,099,000		86,099,000		$ 86,099,000
Accumulated amortization	(78,899,000)		(78,899,000)		(76,088,000)
Net carrying balance	$ 7,200,000		$ 7,200,000		$ 10,011,000