Consolidated Statement of Equity - 6 months ended Jun. 30, 2015 - USD ($) shares in Thousands, $ in Thousands	Total	Series D Preferred Shares of Beneficial Interest [Member]	Series D 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 (loss) [Member]	Non-Controlling Interests [Member]
Beginning balance at Dec. 31, 2014	$ 509,663		$ 120,500	$ 35,809	$ 647,121	$ (322,432)		$ (124)	$ 28,789
Beginning balance, shares at Dec. 31, 2014			4,820	36,401
Net income attributable to Winthrop Realty Trust	9,602					9,602
Net loss attributable to non-controlling interests	(3,423)								(3,423)
Distributions to non-controlling interests	(529)								(529)
Contributions from non-controlling interests	451								451
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 ($0.325 per share)	(11,642)					(11,642)
Dividends declared on Series D Preferred Shares ($1.15625 per share)		$ (5,573)					$ (5,573)
Dividends declared on Restricted Shares	(192)					(192)
Change in unrealized loss on interest rate derivatives	(638)							(638)
Stock issued pursuant to Dividend Reinvestment Plan	178			$ 16	162
Stock issued pursuant to Dividend Reinvestment Plan, shares				16
Amortization of Restricted Shares	1,331				1,331
Ending balance at Jun. 30, 2015	$ 511,855		$ 120,500	$ 35,825	$ 648,614	$ (330,237)		$ (762)	$ 37,915
Ending balance, shares at Jun. 30, 2015			4,820	36,417