Non Controlling Interests (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Schedule of changes in the Trust?s ownership interest in the subsidiaries
Net income attributable to Winthrop Realty Trust	$ 15,108	$ 9,846	$ 26,719	$ 20,772
Decrease In Winthrop Paid in Capital Adjustments From Noncontrolling Interests	0	0	(5,695)	0
Changes From Net Income Attributable And Transfers From Non Controlling Interest	$ 15,108	$ 9,846	$ 21,024	$ 20,772