Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
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Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

+ References

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-Publisher FASB
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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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- Definition

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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No definition available.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

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Equity Compensation (Details Textual) - USD ($)	1 Months Ended		12 Months Ended
Equity Compensation (Details Textual) - USD ($)	Mar. 31, 2017	Apr. 30, 2016	Dec. 31, 2017	Dec. 31, 2016
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted under the plan			12,976
Shares granted under the plan immediately vested			4,556
Omnibus Equity Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized			340,000
Equity compensation expense recorded			$ 123,000	$ 48,000
Unrecognized compensation expense			$ 253,000
Unrecognized compensation expense, expected to be recognized			27 months
Award vesting period			3 years
Shares awarded under the plan, vesting description			Shares awarded under this plan vest in equal thirds on the first three anniversaries of the award date if the employee remains employed with Cortland Bancorp.
Omnibus Equity Plan \| Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted under the plan	12,976	13,683
Director Equity Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity compensation expense recorded			$ 30,000
Shares granted under the plan immediately vested		1,789
Director Equity Plan \| Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized			113,000
Shares granted under the plan immediately vested	1,656