Number of options outstanding, including both vested and non-vested options.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 718
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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No definition available.

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Employee Benefit Plans - SARs Outstanding by Exercise Price Range (Details) - Stock Appreciation Rights (SARs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Prices (in dollars per share)	$ 19.02	$ 20.54	$ 21.64
Number Outstanding (in shares)	73,000	67,000	50,000
SARs Outstanding, Weighted Average Remaining Life	1 year 9 months 11 days
SARs Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 19.02
15.19 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Prices (in dollars per share)	$ 15.19
Number Outstanding (in shares)	18,000
SARs Outstanding, Weighted Average Remaining Life	3 years
SARs Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 15.19
18.12 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Prices (in dollars per share)	$ 18.12
Number Outstanding (in shares)	21,000
SARs Outstanding, Weighted Average Remaining Life	2 years
SARs Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 18.12
21.61 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Prices (in dollars per share)	$ 21.61
Number Outstanding (in shares)	34,000
SARs Outstanding, Weighted Average Remaining Life	1 year
SARs Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 21.61