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Stock Options and Stock Appreciation Rights - Options (Details) - USD ($) |  | 12 Months Ended |
--- | --- | --- | ---
Apr. 18, 2022 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Apr. 05, 2012
Employee Stock Options |  |  |  |  |
Stock option details |  |  |  |  |
Shares available for future grants |  |  |  |  | 800,000
Maximum exercisable period for granted share-based compensation |  | 10 years |  |  |
Black-Scholes-Merton option valuation model assumptions |  |  |  |  |
Expected Life (Years) |  | 7 years | 7 years |  |
Dividend yield (as a percent) |  | 3.08% | 3.18% |  |
Interest rate (as a percent) |  | 1.94% | 1.02% |  |
Volatility (as a percent) |  | 37.78% | 37.84% |  |
Number of options granted (in shares) |  | 31,150 |  |  |
Stock option activity |  |  |  |  |
Options outstanding at the beginning of the period (in shares) |  | 520,551 |  |  |
Plus: Options granted (in shares) |  | 31,150 |  |  |
Less: |  |  |  |  |
Exercise of stock options (in shares) |  | 69,479 |  |  |
Options forfeited (in shares) |  | 20,400 |  |  |
Options outstanding at the end of the period (in shares) |  | 461,822 | 520,551 |  |
Options fully vested and exercisable at the end of the period (in shares) |  | 258,215 |  |  |
Stock Options, Weighted average exercise price |  |  |  |  |
Options outstanding at the beginning, weighted average exercise price (in dollars per share) |  | $ 28.28 |  |  |
Plus: Options granted, weighted average exercise price (in dollars per share) |  | 38.92 |  |  |
Less: |  |  |  |  |
Options exercised, weighted average exercise price (in dollars per share) |  | 22.14 |  |  |
Options forfeited, weighted average exercise price (in dollars per share) |  | 33.99 |  |  |
Options outstanding at the end, weighted average exercise price (in dollars per share) |  | 29.67 | $ 28.28 |  |
Options fully vested and exercisable at the end, weighted average exercise price (in dollars per share) |  | $ 25.26 |  |  |
Stock Options, Weighted average remaining contractual term (years) |  |  |  |  |
Options outstanding at the end, weighted average remaining contractual term (years) |  | 4 years 25 days |  |  |
Options fully vested and exercisable at the end, weighted average remaining contractual term (years) |  | 2 years 3 months 3 days |  |  |
Stock Options, Aggregate intrinsic value |  |  |  |  |
Options outstanding at the end, aggregate intrinsic value |  | $ 7,430,000 |  |  |
Options fully vested and exercisable at the end, aggregate intrinsic value |  | 5,293,000 |  |  |
Stock-based compensation expense |  | 449,000 | $ 506,000 | $ 743,000 |
Stock-based compensation cost, unrecognized, related to non-vested options |  | $ 762,000 |  |  |
Stock-based compensation cost, unrecognized, related to non-vested options, weighted-average period of recognition |  | 1 year 8 months 12 days |  |  |
Other information pertaining to option activity |  |  |  |  |
Weighted average grant date fair value of stock options granted (in dollars per share) |  | $ 11.24 | $ 10.20 | $ 2.46 |
Total fair value of stock options vested |  | $ 514,000 | $ 1,308,000 | $ 1,218,000 |
Total intrinsic value of stock options exercised |  | $ 1,670,000 | $ 2,536,000 | $ 356,000 |
Stock Appreciation Rights |  |  |  |  |
Stock option details |  |  |  |  |
Shares available for future grants | 750,000 |  |  |  |
Maximum exercisable period for granted share-based compensation | 10 years |  |  |  |
Number of rights issued |  | 502,250 |  |  |
Base value of units issued (per unit) |  | $ 39.95 |  |  |
Vesting period | 8 years |  |  |  |
Stock Options, Aggregate intrinsic value |  |  |  |  |
Stock-based compensation expense |  | $ 546,000 |  |  |
Incentive Stock Options to 10 Percent Shareholders |  |  |  |  |
Stock option details |  |  |  |  |
Maximum exercisable period for granted share-based compensation |  | 5 years |  |  |

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- Definition 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). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(01) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iii) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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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 https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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