Accumulated service period for voluntary termination.

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Number of restricted share right will get settled for number of common share.

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Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period After Performance Period

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Awards Issuable Under Outperformance Feature

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- Definition

Share-Based Compensation Arrangement, Number Of Vesting Installments

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Share-Based Compensation Arrangement, Outperformance Feature Measurement Term

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Share-Based Payment Arrangement, Expense Recognized To Date

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Share-based Compensation Arrangement by Share-based Payment Award, Award Issuance, Percentage

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Threshold Age For Qualifying Retirement

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- Definition

Vesting Acceleration Period

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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- Definition

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

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Amount of cost capitalized for award under share-based payment arrangement.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The number of grants made 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).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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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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Number, after forfeiture, of shares or units issued under share-based payment arrangement. Excludes shares or units issued under employee stock ownership plan (ESOP).

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Share Based Compensation - Narrative (Details) $ / shares in Units, $ in Millions						3 Months Ended
	Mar. 04, 2021 shares	Feb. 23, 2021 installment shares	Feb. 01, 2021 shares	Mar. 05, 2020	Feb. 28, 2018	Mar. 31, 2021 USD ($) shares	Mar. 31, 2020 USD ($)	Jan. 20, 2021 $ / shares	Dec. 31, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Voluntary termination of employment age limit						57
Number of vesting installments \| installment		3
Vesting acceleration period		1 year
Restricted Share Rights Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares) \| shares						770,988			488,735
Unrecognized compensation expenses \| $						$ 3.3
Weighted average period over which options will be recognized						2 years 3 days
Share-based compensation expense \| $						$ 2.3	$ 1.9
Share-based compensation expense, capitalized \| $						$ 0.3	0.3
Granted (in shares) \| shares	252,278					301,545
Ratio of restricted share right will get settled for common share	1
Accumulated service period for voluntary termination						15 years
Restricted Share Rights Awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						1 year
Restricted Share Rights Awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years					3 years
Restricted Performance Share Units Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					3 years
Unrecognized compensation expenses \| $						$ 10.0
Weighted average period over which options will be recognized						2 years 3 months 14 days
Share-based compensation expense \| $						$ 0.8	0.6
Share-based compensation expense, capitalized \| $						$ 0.1	$ 0.1
Common shares issued for share based compensation (in shares) \| shares			82,513
Dividends payable (in dollars per share) \| $ / shares								$ 0.19
Executive Officer \| Restricted Performance Share Units Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares) \| shares						906,626			525,669
Granted (in shares) \| shares						380,957
Performance earning potential				200.00%
Outperformance feature measurement term				3 years		3 years
Vesting period after outperformance feature measurement term						2 years
Executive Officer \| Restricted Performance Share Units Plan \| 2021 Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards issuable under outperformance feature (in shares) \| shares						388,840
Share-based compensation expense recognized to date \| $						$ 0.0
Executive Officer \| Restricted Performance Share Units Plan \| 2020 Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards issuable under outperformance feature (in shares) \| shares						316,236
Share-based compensation expense recognized to date \| $						$ 0.0
Executive Officer \| Restricted Performance Share Units Plan \| 2019 Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards issuable under outperformance feature (in shares) \| shares						228,858
Share-based compensation expense recognized to date \| $						$ 0.2
Non Officer Employees \| Restricted Performance Share Units Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares) \| shares		49,267