The market price at the grant date for the Performance Units granted.

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Represents the amount of difference between the fair value of the underlying shares reserved for issuance and exercise price of vested portions of options and SARs outstanding and currently exercisable.

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Represents the number of shares into which the fully or partially vested stock options and SARs outstanding, as of the balance sheet date, can be currently converted under the plan.

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Share Based Compensation Arrangement By Share Based Payment Award, Options And SARs, Grants In Period

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Represents the number of non-vested options and SARs outstanding.

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No definition available.

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Represents the weighted average grant date fair value of non-vested options and SARs outstanding.

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No definition available.

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As of the balance sheet date, aggregate intrinsic value of fully vested and expected to vest options and stock appreciation rights outstanding.

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Represents the number of shares into which fully vested and expected to vest stock options and SARs outstanding can be converted under the option plan as of the balance sheet date.

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No definition available.

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Represents the number of stock options and SARs that vested during the reporting period.

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Represents the aggregate grant date fair value of stock options and SARs that vested during the reporting period.

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No definition available.

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Represents the high end of the range of the payout depending on the achievement of goals.

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No definition available.

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Represents the low end of the range of the payout depending on the achievement of goals.

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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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The weighted average fair value at grant date for nonvested equity-based awards issued 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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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Percentage of vesting of award under share-based payment arrangement.

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Stock Compensation Plan (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019
Options
Stock options and Stock Appreciation Rights vested
Options granted (in shares)				0
Options vested (in shares)				73,828
Aggregate grant date fair value of Options vested (in millions)				$ 1.1
Outstanding Stock Options and Stock Appreciation Rights
Options outstanding (in shares)				386,053	416,548
Aggregate intrinsic value (in millions)				$ 0.3	$ 3.9
Per share weighted average exercise price (in usd per share)				$ 70.68	$ 70.08
Exercisable Options (in shares)				368,775	318,029
Aggregate intrinsic value (in millions)				$ 0.3	$ 3.9
Unvested Options (in shares)				17,278	98,519
Per share weighted average grant date fair value (in usd per share)				$ 14.61	$ 14.41
Performance Share Units ("PSUs")
Additional disclosures
Granted (in shares)				44,206
Percentage of target to be awarded, low end of range				0.00%
Percentage of target to be awarded, high end of range				200.00%
Market price at grant date of performance units (in usd per share)				$ 63.07
Employees \| Restricted Stock Units (RSUs)
Additional disclosures
Granted (in shares)				79,977
Equity instruments other than options, weighted average grant date fair value (in usd per share)				$ 62.04
Employees \| Scenario, Forecast \| Vesting Tranche One \| Restricted Stock Units (RSUs)
Additional disclosures
Award vesting rights			33.33%
Employees \| Scenario, Forecast \| Vesting Tranche Two \| Restricted Stock Units (RSUs)
Additional disclosures
Award vesting rights		33.33%
Employees \| Scenario, Forecast \| Vesting Tranche Three \| Restricted Stock Units (RSUs)
Additional disclosures
Award vesting rights	33.33%
Directors \| Restricted Stock Units (RSUs)
Additional disclosures
Granted (in shares)				14,112
Equity instruments other than options, weighted average grant date fair value (in usd per share)				$ 49.60
Award vesting period				1 year