Share-Based Payments and Employee Benefits - ESPP (Details) - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award
Proceeds from common shares issued pursuant to ESPP	$ 1,594,000	$ 1,715,000	$ 1,457,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares authorized	2,100,000
Option to purchase	$ 25,000
Percentage of discount	15.00%
Common shares available for issuance	1,900,000
Common shares issued pursuant to employee share purchase plan (in shares)	64,321	68,047	47,022
Proceeds from common shares issued pursuant to ESPP	$ 1,600,000	$ 1,700,000	$ 1,500,000
Risk-free interest rate	0.10%
Expected life	6 months	6 months	6 months
Minimum \| ESPP
Share-based Compensation Arrangement by Share-based Payment Award
Expected volatility	22.00%	13.00%	18.00%
Dividend yield	1.50%	1.10%	2.60%
Risk-free interest rate		0.10%	2.20%
Maximum \| ESPP
Share-based Compensation Arrangement by Share-based Payment Award
Expected volatility	39.00%	67.00%	28.00%
Dividend yield	3.10%	3.30%	3.50%
Risk-free interest rate		1.70%	2.40%

Share-based Compensation Arrangement by Share-based Payment Award, Maximum Value of Share Per Employee

No definition available.

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- Definition

The cash inflow associated with the amount received from the stock plan during the period.

+ References

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Discount rate from fair value on purchase date that participants pay for shares.

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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

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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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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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

Number of shares authorized for issuance under share-based payment arrangement.

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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.

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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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Number of shares issued during the period as a result of an employee stock purchase plan.

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