Stock-Based Compensation Plans - Equity Incentive Plan (Details) - 2018 Equity Inventive Plan - shares	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
2018 Plan Number of Shares
Awards available for issuance, beginning balance (in shares)	188,400	194,025
Awards granted (in shares)	(7,400)	(5,625)
Awards forfeited (in shares)	100
Awards available for issuance, ending balance (in shares)	181,100	188,400

Share-based Compensation Arrangement by Share-based Payment Award, Shares Forfeited

No definition available.

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Definition

Number of shares issued under share-based payment arrangement.

+ References

+ Details

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- Details

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