Share-Based Payments (Black Scholes Option Pricing Model Assumptions) (Details)	9 Months Ended	12 Months Ended
Sep. 30, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.13%	0.12%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	2 years 2 months 12 days	3 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	9 years 2 months 12 days	10 years
Weighted-average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, weighted-average	21.93%	22.14%
Risk-free rate, weighted-average	1.70%	2.58%

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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- Definition

Rate of weighted-average expected volatility for award under share-based payment arrangement.

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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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No definition available.

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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

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