Consolidated Balance Sheets (Parenthetical) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Real Estate Owned, Accumulated Depreciation	$ 1,142,513,000	$ 1,062,087,000
Treasury Stock, Shares	7,413,853	7,315,087
Common Shares, par value	$ 0.01	$ 0.01
Common Shares, shares authorized	100,000,000	100,000,000
Preferred Shares, par value	$ 0.01	$ 0.01
Preferred Shares, shares authorized	25,000,000	25,000,000
Series C Preferred Shares [Member]
Preferred Shares, shares issued	5,392,916	5,394,050
Preferred Shares, liquidation preference	$ 134,822,900	$ 134,822,900
Series E Preferred Shares [Member]
Preferred Shares, shares issued	3,447,381	3,447,381
Preferred Shares, liquidation preference	$ 86,184,525	$ 86,184,525
Series G Preferred Stock [Member]
Preferred Shares, shares issued	6,000,000	6,000,000
Preferred Shares, liquidation preference	$ 150,000,000	$ 150,000,000