Consolidated Statements of Shareholders' Equity (USD $) In Thousands	Total	Preferred Shares of Beneficial Interest	Common Shares of Beneficial Interest	Additional Paid-In Capital	Accumulated Distributions in Excess of Net Income	Accumulated Other Comprehensive Income (Loss)	Non- Controlling Interests
Beginning balance at Dec. 31, 2009	$ 229,200		$ 20,375	$ 498,118	$ (301,317)	$ (87)	$ 12,111
Beginning balance, shares at Dec. 31, 2009			20,375
Net income (loss) attributable to Winthrop Realty Trust	16,477				16,477
Net income attributable to non-controlling interests	888						888
Distributions to non-controlling interests	(354)						(354)
Contributions from non-controlling interests	1,431						1,431
Dividends paid or accrued on Common Shares of Beneficial interest ($0.65, $0.65 and $0.65 per share in 2010, 2011 and 2012 respectively)	(15,654)				(15,654)
Dividends paid or accrued on Series C Preferred Shares ($1.625 and $1.43 per share in 2010, 2011 respectively)	(288)				(288)
Change in unrealized loss on available for sale securities, net of reclassification adjustments for amounts included in net income	2					2
Change in unrealized gain on interest rate derivatives	22					22
Conversion of Series C Preferred Shares to Common Shares, value	8,948		714	8,234
Conversion of Series C Preferred Shares to Common Shares, Shares			714
Net proceeds from Common Shares offering/Series D Preferred Share offering	66,774		5,750	61,024
Net proceeds from Common Shares offering/Series D Preferred Share offering, shares			5,750
Stock issued pursuant to dividend reinvestment plan	2,401		191	2,210
Stock issued pursuant to dividend reinvestment plan, shares			191
Ending balance at Dec. 31, 2010	309,847		27,030	569,586	(300,782)	(63)	14,076
Ending balance, shares at Dec. 31, 2010			27,030
Net income (loss) attributable to Winthrop Realty Trust	10,933				10,933
Net income attributable to non-controlling interests	814						814
Distributions to non-controlling interests	(356)						(356)
Contributions from non-controlling interests	6,526						6,526
Dividends paid or accrued on Common Shares of Beneficial interest ($0.65, $0.65 and $0.65 per share in 2010, 2011 and 2012 respectively)	(20,473)				(20,473)
Dividends paid or accrued on Series C Preferred Shares ($1.625 and $1.43 per share in 2010, 2011 respectively)	(585)				(585)
Dividends paid or accrued on Series D Preferred Shares ($0.212 and $1.92628 per share in 2011, 2012 respectively)	(339)				(339)
Change in unrealized gain on interest rate derivatives	(55)					(29)	(26)
Net proceeds from Common Shares offering/Series D Preferred Share offering	61,386		5,750	55,636
Net proceeds from Common Shares offering/Series D Preferred Share offering, shares			5,750
Net proceeds from Series D Preferred Shares offering	38,378	40,000		(1,622)
Net proceeds from Series D Preferred Shares offering, shares		1,600
Stock issued pursuant to dividend reinvestment plan	2,760		261	2,499
Stock issued pursuant to dividend reinvestment plan, shares			261
Ending balance at Dec. 31, 2011	408,836	40,000	33,041	626,099	(311,246)	(92)	21,034
Ending balance, shares at Dec. 31, 2011		1,600	33,041
Net income (loss) attributable to Winthrop Realty Trust	24,631				24,631
Net income attributable to non-controlling interests	(247)						(247)
Distributions to non-controlling interests	(7,242)						(7,242)
Contributions from non-controlling interests	4,576						4,576
Purchase of non-controlling interests	(7,900)			(4,533)			(3,367)
Dividends paid or accrued on Common Shares of Beneficial interest ($0.65, $0.65 and $0.65 per share in 2010, 2011 and 2012 respectively)	(21,485)				(21,485)
Dividends paid or accrued on Series D Preferred Shares ($0.212 and $1.92628 per share in 2011, 2012 respectively)	(9,285)				(9,285)
Change in unrealized gain on interest rate derivatives	42					42
Net proceeds from Common Shares offering/Series D Preferred Share offering	77,563	80,500		(2,937)
Net proceeds from Common Shares offering/Series D Preferred Share offering, shares		3,220
Stock issued pursuant to dividend reinvestment plan	517		48	469
Stock issued pursuant to dividend reinvestment plan, shares			48
Stock buyback	(742)		(70)	(672)
Stock buyback, shares			(70)
Ending balance at Dec. 31, 2012	$ 469,264	$ 120,500	$ 33,019	$ 618,426	$ (317,385)	$ (50)	$ 14,754
Ending balance, shares at Dec. 31, 2012		4,820	33,019