Consolidated Statements of Equity (USD $) In Thousands	Total	Series D Preferred Shares of Beneficial Interest [Member]	Series D Preferred Shares of Beneficial Interest [Member]	Series D Preferred Shares of Beneficial Interest [Member]	Common Shares of Beneficial Interest [Member]	Common Shares of Beneficial Interest [Member] Series D Preferred Shares of Beneficial Interest [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] Series D Preferred Shares of Beneficial Interest [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]	Accumulated Other Comprehensive Income (loss) [Member] Series D Preferred Shares of Beneficial Interest [Member]	Non-Controlling Interests [Member]	Non-Controlling Interests [Member] Series D Preferred Shares of Beneficial Interest [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	33,848		0		0		0		33,848		0		0
Net loss attributable to non-controlling interests	(2,419)		0		0		0		0		0		(2,419)
Distributions to non-controlling interests	(52)		0		0		0		0		0		(52)
Contributions from non-controlling interests	861		0		0		0		0		0		861
Purchase of non-controlling interests	(150)		0		0		103		0		0		(253)
Dividends declared, paid or accrued on Common Shares of Beneficial Interest ($0.325 per share declared and $0.4875 per share paid or accrued)	(16,553)		0		0		0		(16,553)		0		0
Dividends declared on Series D Preferred Shares ($1.15625 per share)	(8,360)	(8,360)		0		0		0		(8,360)		0		0
Dividends declared, paid or accrued on Restricted Shares	(235)		0		0		0		(211)		0		0
Change in unrealized loss on interest rate derivatives	(20)		0		0		0		0		(20)		0
Stock issued pursuant to Dividend Reinvestment Plan	353		0		29		324		0		0		0
Stock issued pursuant to Dividend Reinvestment Plan, shares					29
Net proceeds from common shares offering, value	29,960		0		2,750		27,210		0		0		0
Net proceeds from Common shares offering, shares					2,750
Issuance of restricted shares, value	0		0				0		0		0		0
Issuance of restricted shares, shares					600
Amortization of Restricted Shares	557		0		0		557		0		0		0
Ending balance at Sep. 30, 2013	507,078		120,500		35,798		646,620		(308,661)		(70)		12,891
Ending balance, shares at Sep. 30, 2013			4,820		36,398
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	12,481				0		0		12,481		0		0
Net loss attributable to non-controlling interests	(3,818)				0		0		0		0		(3,818)
Distributions to non-controlling interests	(711)				0		0		0		0		(711)
Contributions from non-controlling interests	873				0		0		0		0		873
Increase in non-controlling interest due to consolidation of property	16,391				0		0		0		0		16,391
Decrease in non-controlling interest due to property sale	(3,764)				0		0		0		0		(3,764)
Dividends declared, paid or accrued on Common Shares of Beneficial Interest ($0.325 per share declared and $0.4875 per share paid or accrued)	(11,642)				0		0		(11,642)		0		0
Dividends declared on Series D Preferred Shares ($1.15625 per share)	(6,502)	(6,502)								(6,502)		0		0
Dividends declared, paid or accrued on Restricted Shares	(192)				0		0		(192)		0		0
Change in unrealized loss on interest rate derivatives	(193)				0		0		0		(193)		0
Stock issued pursuant to Dividend Reinvestment Plan	178				16		162		0		0		0
Stock issued pursuant to Dividend Reinvestment Plan, shares			0		16
Amortization of Restricted Shares	1,450				0		1,450		0		0		0
Ending balance at Jul. 31, 2014	$ 514,214		$ 120,500		$ 35,825		$ 648,733		$ (328,287)		$ (317)		$ 37,760
Ending balance, shares at Jul. 31, 2014			4,820		36,417