Stock-Based Compensation Summary Information for Options Granted (Details) - $ / shares	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	23,218	14,755
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term in years	10 years	10 years
Expected volatility	33.00%	37.00%
Weighted average market price on date of grants	$ 29.84	$ 34.33
Options granted, per share weighted average fair value	$ 8.70	$ 11.98
Weighted Average \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	2.75%	2.10%
Expected life in years	6 years 6 months	6 years 6 months
Risk-free interest rate	2.58%	2.86%
Fair Value as a percentage of market value at grant date	29.00%	35.00%

Share-based Compensation Arrangement by Share-based Payment Award, Fair Value as a Percent of Market Value

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Market Price

+ References

No definition available.

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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.

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- Definition

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

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Weighted average expected volatility rate of share-based compensation awards.

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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.

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- Definition

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

+ 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.

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- Definition

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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Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ 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
-Subparagraph (f)(2)(i)
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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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