The maximum amount of compensation expense incurred on the reporting period.

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Estimated amount of compensation expense excepted to be recorded.

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- Definition

The period of performance for options under LTIP.

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Share based compensation reduction Of expense

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Description about the Period in which option vested or expired.

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Unrecognized compensation expense of reporting period.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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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).

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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Number of shares authorized for issuance under share-based payment arrangement.

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Gross number of share options (or share units) granted during the period.

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

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Stock Compensation Plans - Additional information (Details) - USD ($)	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	35,661				35,661		35,661
Stock Option Period, Description					All options expire ten years from the date of grant. Vested options of retirees expire on the earlier of the scheduled expiration date or one year after the retirement date.
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition					1 month
Allocated Share-based Compensation Expense	$ 245,000		$ 331,000		$ 506,000	$ 557,000
Compensation Expense, Maximum	6,900,000				6,900,000
Estimated Compensation Expense, Excepted	4,600,000				4,600,000
Unrecognized Compensation Expense	1,800,000				1,800,000
Reduction of expense	$ 88,000		$ 325,000		$ 411,000	$ 650,000
Executive Long-Term Equity Incentive Plan [Member]
Stock Option Period, Description					The value of awards issued in 2021 and 2022 under the Executive LTIP will be determined individually at the end of each respective 36 month performance period ending December 31. The benefits earned under these LTIPs will be paid out in equity in the first quarter following the end of the performance period. The participants will receive all or a portion of the award if their employment is terminated by the Company without cause, by the participant in certain situations, or by death, disability or retirement.
Share-based Compensation, Performance Period					3 years
Executive Long-Term Equity Incentive Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	20.00%				20.00%
Executive Long-Term Equity Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	50.00%				50.00%
Equity Plan 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	900,000				900,000
Long Term Equity Incentive Plan2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,200,000				1,200,000
Short Term Equity Incentive Plan 2015 [Member]
Stock Option Period, Description					The final amount of benefits under the STIPs is determined as of December 31 of the same year and paid out in cash in the first quarter of the following year.
Performance Stock Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross		86,190			86,190
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	247,864				247,864		161,674
Performance Stock Units (PSUs) [Member] \| Executive Long-Term Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross		86,190
Restricted Stock Awards (RSAs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross					44,192
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	67,240				67,240		58,260
Restricted Stock Awards (RSAs) [Member] \| Key Long-Term Equity Incentive Plan 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross		19,612
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross					24,580
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period					3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	34,223				34,223		51,773
Restricted Stock Units (RSUs) [Member] \| Key Long-Term Equity Incentive Plan 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross				17,542
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period					3 years
Restricted Stock Units (RSUs) [Member] \| Key Long-Term Equity Incentive Plan 2015 [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	5.00%				5.00%
Restricted Stock Units (RSUs) [Member] \| Key Long-Term Equity Incentive Plan 2015 [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	10.00%				10.00%
Restricted Share Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	349,327				349,327
Short Term Incentive Plan [Member]
Allocated Share-based Compensation Expense					$ 215,000		$ 2,700,000
Restricted Stock Grants [Member] \| Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross					24,580
Restricted Stock Grants [Member] \| Share-based Compensation Award, Tranche One [Member] \| Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross					14,712