| Investments In Unconsolidated Joint Ventures (BNES Associates III) (Narrative) (Details) (USD $) | 9 Months Ended | ||
|---|---|---|---|
| Sep. 30, 2013
 The Offices At Crystal Lake, L.L.C. [Member] | Oct. 23, 2012
 BNES Associates III's Interest In The Offices At Crystal Lake [Member] | Oct. 23, 2012
 BNES Associates III [Member]
 sqft | |
| Schedule of Equity Method Investments [Line Items] | |||
| Indirect residual ownership percentage | 31.25% | ||
| Area of property (in square feet) | 106,345 | ||
| Percentage of interest in venture | 50.00% | ||
| Investment ownership percentage | 62.50% | ||
| Mortgage loans, carrying amount | $ 7,500,000 | ||
| Interest rate | 4.76% | ||
| Mortgage loan, maturity date | November 2023 | ||
| X | ||||||||||
| 
- Definition Indirect Residual Ownership Percentage No definition available. 
 | 
| X | ||||||||||
| 
- Definition Investment Ownership Percentage No definition available. 
 | 
| X | ||||||||||
| 
- Definition Mortgage Loan Maturity Date No definition available. 
 | 
| X | ||||||||||
| 
- Definition Area of a real estate property. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Contractual interest rate for funds borrowed, under the debt agreement. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition The carrying amount of the outstanding balance due under the mortgage loan. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Details 
 |