Common Shares (Activity Under At-The-Market Share Offering Program) (Details) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Common shares sold	0	3,599	0
2017 ATM program [Member]
Total net consideration		$ 24,800,000
Common shares sold		200,000

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

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