Variable Interest Entities - The Accompanying Unaudited Pro Forma Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Variable Interest Entities [Abstract]
Total revenue	$ 18,842	$ 18,151	$ 59,502	$ 57,913
Consolidated net income	10,133	16,010	30,797	26,591
Net income attributable to Winthrop Realty Trust	$ 11,128	$ 15,660	$ 33,489	$ 28,207
Per common share data-basic	$ 0.25	$ 0.39	$ 0.76	$ 0.66
Per common share data-diluted	$ 0.25	$ 0.39	$ 0.76	$ 0.66

Business acquisitions proforma profit loss.

No definition available.

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- Details

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- Definition

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

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- Definition

The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

+ Details

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- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

+ Details

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- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

+ Details

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