Dividends (Details) - $ / shares			12 Months Ended
	Nov. 04, 2021	Sep. 29, 2017	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Preferred shares, percentage			5.00%	5.00%	5.00%
Dividends declared to common shareholders	$ 1.07		$ 4.26	$ 4.22	$ 4.14
Common shares, paid			4.250	4.210	4.110
Payments of ordinary dividends, common stock			3.358	3.452	4.110
Common shares, capital gain			0.680	0	0
Return of capital, common shares			$ 0.212	$ 0.758	$ 0
5.417% Series 1 Cumulative Convertible Preferred Shares
Class of Stock [Line Items]
Preferred shares, percentage			5.417%	5.417%	5.417%
Preferred shares, declared			$ 1.354	$ 1.354	$ 1.354
Preferred shares, paid			1.354	1.354	1.354
Payment of ordinary dividends, preferred stock			1.124	1.354	1.354
Preferred shares, capital gain			$ 0.230	$ 0	$ 0
5.0% Series C Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Preferred shares, percentage		5.00%	5.00%	5.00%	5.00%
Preferred shares, declared			$ 1.250	$ 1.250	$ 1.250
Preferred shares, paid			1.250	1.250	1.250
Payment of ordinary dividends, preferred stock			1.038	1.250	1.250
Preferred shares, capital gain			$ 0.212	$ 0	$ 0