Consolidated Statements of Equity (Unaudited) (USD $) In Thousands	Total	Cumulative Redeemable Series D Preferred Shares	Common Shares of Beneficial Interest	Additional Paid-In Capital	Accumulated Distributions in Excess of Net Income	Accumulated Other Comprehensive Income	Non- Controlling Interests
Beginning balance at Dec. 31, 2010	$ 309,847		$ 27,030	$ 569,586	$ (300,782)	$ (63)	$ 14,076
Beginning balance, shares at Dec. 31, 2010			27,030
Net income attributable to Winthrop Realty Trust	20,772				20,772
Net income attributable to non-controlling interests	851						851
Distributions to non-controlling interests	(327)						(327)
Contributions from non-controlling interests	300						300
Dividends paid or accrued on Common Shares of Beneficial Interest ($0.325 per share)	(15,104)				(15,104)
Dividends paid or accrued on Series C Preferred Shares ($0.8125 per share) and Series D Preferred Shares ($1.15625 per share)	(176)				(176)
Change in unrealized gain on interest rate derivatives	63					63
Net proceeds from Common shares offering	61,386		5,750	55,636
Net proceeds from Common shares offering, shares			5,750
Stock issued pursuant to dividend reinvestment plan	2,064		179	1,885
Stock issued pursuant to dividend reinvestment plan, shares			179
Ending balance at Sep. 30, 2011	379,676		32,959	627,107	(295,290)		14,900
Ending balance, shares at Sep. 30, 2011			32,959
Beginning balance at Dec. 31, 2011	408,836	40,000	33,041	626,099	(311,246)	(92)	21,034
Beginning balance, shares at Dec. 31, 2011		1,600	33,041
Net income attributable to Winthrop Realty Trust	26,719				26,719
Net income attributable to non-controlling interests	(435)						(435)
Distributions to non-controlling interests	(6,115)						(6,115)
Contributions from non-controlling interests	4,340						4,340
Purchase of non-controlling interests	(6,250)			(5,695)			(555)
Dividends paid or accrued on Common Shares of Beneficial Interest ($0.325 per share)	(16,119)				(16,119)
Dividends paid or accrued on Series C Preferred Shares ($0.8125 per share) and Series D Preferred Shares ($1.15625 per share)	(6,498)				(6,498)
Change in unrealized gain on interest rate derivatives	(73)					(73)
Net proceeds from Common shares offering	77,572	80,500		(2,928)
Net proceeds from Common shares offering, shares		3,220
Stock issued pursuant to dividend reinvestment plan	397		36	361
Stock issued pursuant to dividend reinvestment plan, shares			36
Ending balance at Sep. 30, 2012	$ 482,374	$ 120,500	$ 33,077	$ 617,837	$ (307,144)	$ (165)	$ 18,269
Ending balance, shares at Sep. 30, 2012		4,820	33,077