| Discontinued Operations (Narrative) (Details) (Moorestown, New Jersey [Member]) | Dec. 31, 2012
 item | 
|---|---|
| Moorestown, New Jersey [Member] | |
| Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | |
| Number of office buildings | 3 | 
| X | ||||||||||
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- Definition Number Of Buildings No definition available. 
 | 
| X | ||||||||||
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- Details 
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