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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

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Nominal or face amount used to calculate payment on derivative.

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Fair value as of the balance sheet date of all derivatives not designated as hedging instruments.

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Derivative Financial Instruments (Narrative Disclosures) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Derivatives
Fair value of interest rate swaps	$ 32,377,000		$ 32,377,000		$ 49,377,000
Interest rate swap contracts not designated as hedging instruments - liabilities, gross	32,377,000		32,377,000		$ 49,377,000
Derivative asset, fair value, amount offset against collateral	0		0
Pretax unrealized gain on interest rates swaps designated as cash flow hedges	(271,000)	$ (418,000)	1,818,000	$ (4,043,000)
Gain recognized in income on ineffective portion of hedges	0
To commercial borrowers, corporation receives fixed rates and pays floating rates
Derivatives
Fair value of interest rate swaps	32,400,000		32,400,000
Interest rate swap contracts not designated as hedging instruments - liabilities, gross	4,700,000		4,700,000
To dealer countparties, corporation pays fixed rates and receives floating rates
Derivatives
Fair value of interest rate swaps	4,700,000		4,700,000
Interest rate swap contracts not designated as hedging instruments - liabilities, gross	32,400,000		32,400,000
Interest rate derivative instruments not designated as hedging instruments at fair value, net	27,700,000		27,700,000
Not Designated as Hedging Instrument \| To commercial borrowers, corporation receives fixed rates and pays floating rates
Derivatives
Derivative, Notional Amount	637,000,000.0		637,000,000.0
Not Designated as Hedging Instrument \| To dealer countparties, corporation pays fixed rates and receives floating rates
Derivatives
Derivative, Notional Amount	637,000,000.0		637,000,000.0
Designated as Hedging Instrument \| Interest rate swaps
Derivatives
Derivative, Notional Amount	$ 114,000,000.0		$ 114,000,000.0