Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
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Fair value, after effects of master netting arrangements, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset offset against an obligation to return collateral. Includes assets not subject to a master netting arrangement and not elected to be offset.

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-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
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Aggregate net fair value of all derivative instruments designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Date the derivative contract matures, in CCYY-MM-DD format.

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Description of where the net gain (loss) on interest rate derivatives not designated as hedging instruments are reported in the statement of income or other statement of financial performance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Fair value as of the balance sheet date of all derivative assets not designated as hedging instruments.

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

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

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Amount before tax, after reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Derivative Financial Instruments (Narrative Disclosures) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivatives
Interest rate swaps - assets	$ 942,000	$ 352,000
Interest rate swaps - liabilities	942,000	352,000
Derivative asset, fair value, amount offset against collateral	0
Derivative hedging instruments	22,000,000	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	$ (122,000)	$ 0	$ 0
Interest rate derivatives, line item on income statement for gain (loss)	other non-interest income
To commercial borrowers, corporation receives fixed rates and pays floating rates
Derivatives
Interest rate swaps - assets	$ 942,000
To commercial borrowers, corporation receives fixed rates and pays floating rates \| Minimum
Derivatives
Derivative, maturity date	Sep. 30, 2018
To commercial borrowers, corporation receives fixed rates and pays floating rates \| Maximum
Derivatives
Derivative, maturity date	May 15, 2034
To dealer countparties, corporation pays fixed rates and receives floating rates
Derivatives
Interest rate swaps - liabilities	$ 942,000
Interest rate derivative instruments not designated as hedging instruments at fair value, net	$ (942,000)
To dealer countparties, corporation pays fixed rates and receives floating rates \| Minimum
Derivatives
Derivative, maturity date	Sep. 30, 2018
To dealer countparties, corporation pays fixed rates and receives floating rates \| Maximum
Derivatives
Derivative, maturity date	May 15, 2034
Not designated as hedging instrument \| To commercial borrowers, corporation receives fixed rates and pays floating rates
Derivatives
Derivative, notional amount	$ 53,400,000
Not designated as hedging instrument \| To dealer countparties, corporation pays fixed rates and receives floating rates
Derivatives
Derivative, notional amount	$ 53,400,000