Share Based Compensation Arrangement by Share Based Payment Award, Fair Value Assumptions, Volatility

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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

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ 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)(iv)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

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.

+ References

No definition available.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ 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 (d)(1)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

+ 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)(1)(iv)(02)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ 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)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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Stock Option Plan - Stock Options Issued (Detail)	12 Months Ended
Stock Option Plan - Stock Options Issued (Detail)	Dec. 31, 2022 $ / shares	Dec. 31, 2021 $ / shares	Dec. 31, 2020 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in usd per share)	$ 44.44	$ 45.07	$ 49.19
Directors \| May, 13 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in usd per share)	47.90
Fair value per option (in usd per share)	$ 8.34
Volatility	0.3000
Expected life (years)	5 years
Assumed yield	4.90%
Risk-free rate	2.89%
Directors \| May 7, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in usd per share)	$ 43.89
Fair value per option (in usd per share)	$ 6.32
Volatility	0.2970
Expected life (years)	5 years
Assumed yield	4.96%
Risk-free rate	0.77%
Directors \| April 24, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in usd per share)	$ 50.00
Fair value per option (in usd per share)	$ 0.84
Volatility	0.2580
Expected life (years)	5 years
Assumed yield	3.80%
Risk-free rate	0.36%
Officers \| May, 13 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in usd per share)	$ 47.90
Fair value per option (in usd per share)	$ 7.66
Volatility	0.2710
Expected life (years)	7 years
Assumed yield	4.93%
Risk-free rate	2.95%
Officers \| May 7, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in usd per share)	$ 43.89
Fair value per option (in usd per share)	$ 5.96
Volatility	0.2750
Expected life (years)	7 years
Assumed yield	4.97%
Risk-free rate	1.24%
Officers \| April 24, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in usd per share)	$ 50.00
Fair value per option (in usd per share)	$ 0.92
Volatility	0.2400
Expected life (years)	7 years
Assumed yield	3.85%
Risk-free rate	0.51%