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Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate, Bonus

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

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Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

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Amount of cost for defined contribution plan.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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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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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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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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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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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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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.

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Number of shares issued under share-based payment arrangement.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Purchase price of common stock expressed as a percentage of its fair value.

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Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited.

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The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

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Compensation Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 01, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased				95,907			2,000,000
Share-based compensation expense				$ 4,178	$ 4,032	$ 3,452
Tax benefit from compensation expense				$ 200	500	1,600
Award vesting period				3 years
Total unrecognized compensation cost for nonvested stock units				$ 5,000
Number of shares issued upon completion of performance cycle		62,649	99,308
Employee minimum age to participate in plan				21 years
Company contributions, amount charged to expense				$ 3,800	$ 3,200	2,800
Preferred stock, shares authorized				5,000,000	5,000,000
Preferred stock, par value				$ 0.01	$ 0.01
Preferred stock, shares outstanding				0	0
Expected years to recognize unearned compensation				2 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term				10 years
Stock Appreciation Rights (SSARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				5 years
Contractual term				10 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense				$ 2,613	$ 1,969	1,211
Total unrecognized compensation cost for nonvested stock units				$ 3,899	$ 3,417	$ 2,175
Number of shares issued				88,759
Expected years to recognize unearned compensation				1 year 10 months 24 days	1 year 10 months 24 days	2 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense				$ 1,097	$ 1,699	$ 2,067
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent				85.00%
Share-based compensation expense				$ 468	$ 364	$ 174
Number of shares authorized				750,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period				58,195	41,116	14,799
Minimum \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				3 years
Minimum \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				2 years
Maximum \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				5 years
Maximum \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				5 years
Stock Plan for Non-Management Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant				86,616	96,031
Number of shares authorized				200,000
Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant, Excluding Deferred Shares				80,130
Share Based Compensation Arrangement by Shar Based Payment Award Number of Shares Available for Grant, Deferred Shares				6,486
Deferred Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate				25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate, Bonus				100.00%
Deferred Compensation Plan Assets				$ 3,600
Deferred Compensation Liability, Current and Noncurrent				$ 4,900
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued upon completion of performance cycle	23,251