Statements Of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2017
Statements Of Equity [Abstract]
Issuance of preferred shares, shares	43,600	23,200
Redemption of preferred shares, shares	42,000	36,900
Issuance of common shares in connection with share-based compensation, shares	287,734	564,583
Common shareholders and restricted share unitholders, per share distribution	$ 8.00	$ 8.00