Real Estate Assets, Discontinued Operations and Assets Held for Sale (Allocation of Shareholders' Income (Loss) Between Continuing and Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Discontinued Operations
Income from continuing operations attributable to common shareholders	$ 494,817	$ 71,783	$ 749,996	$ 130,989
Income from discontinued operations attributable to common shareholders	0	40	0	110
Net income attributable to common shareholders	$ 494,817	$ 71,823	$ 749,996	$ 131,099