Consolidated Statements of Equity (USD $) In Thousands	Total	Series D Preferred Shares of Beneficial Interest [Member]	Preferred Shares of Beneficial Interest [Member]	Common Shares of Beneficial Interest [Member]	Additional Paid-In Capital [Member]	Accumulated Distributions in Excess of Net Income [Member]	Accumulated Distributions in Excess of Net Income [Member] Series D Preferred Shares of Beneficial Interest [Member]	Accumulated Other Comprehensive Income [Member]	Non-Controlling Interests [Member]
Beginning balance at Dec. 31, 2012	$ 469,264		$ 120,500	$ 33,019	$ 618,426	$ (317,385)		$ (50)	$ 14,754
Beginning balance, shares at Dec. 31, 2012			4,820	33,019
Net income attributable to Winthrop Realty Trust	13,746					13,746
Net loss attributable to non-controlling interests	(795)								(795)
Distributions to non-controlling interests
Contributions from non-controlling interests	535								535
Purchase of non-controlling interests	(75)				52				(127)
Dividends declared on Common Shares of Beneficial Interest ($0.1625 per share)	(5,367)					(5,367)
Dividends declared on Series D Preferred Shares ($0.578125 per share)		(2,787)					(2,787)
Dividends declared on Restricted Shares
Change in unrealized loss on interest rate derivatives	(1)							(1)
Stock issued pursuant to Dividend Reinvestment Plan	115			10	105
Stock issued pursuant to Dividend Reinvestment Plan, shares				10
Issuance of Restricted Shares, Value
Issuance of Restricted Shares				100
Amortization of Restricted Shares	43				43
Ending balance at Mar. 31, 2013	474,678		120,500	33,029	618,626	(311,793)		(51)	14,367
Ending balance, shares at Mar. 31, 2013			4,820	33,129
Beginning balance at Dec. 31, 2013	509,663		120,500	35,809	647,121	(322,432)		(124)	28,789
Beginning balance, shares at Dec. 31, 2013			4,820	36,401
Net income attributable to Winthrop Realty Trust	641					641
Net loss attributable to non-controlling interests	(1,443)								(1,443)
Distributions to non-controlling interests	(20)								(20)
Contributions from non-controlling interests	149								149
Increase in non-controlling interest due to consolidation of property	16,391								16,391
Decrease in non-controlling interest due to property sale	(3,764)								(3,764)
Dividends declared on Common Shares of Beneficial Interest ($0.1625 per share)	(5,820)					(5,820)
Dividends declared on Series D Preferred Shares ($0.578125 per share)		(2,787)					(2,787)
Dividends declared on Restricted Shares	(96)					(96)
Change in unrealized loss on interest rate derivatives	(145)							(145)
Stock issued pursuant to Dividend Reinvestment Plan	91			8	83
Stock issued pursuant to Dividend Reinvestment Plan, shares				8
Amortization of Restricted Shares	414				414
Ending balance at Mar. 31, 2014	$ 513,274		$ 120,500	$ 35,817	$ 647,618	$ (330,494)		$ (269)	$ 40,102
Ending balance, shares at Mar. 31, 2014			4,820	36,409