Unsecured Revolving Credit Facility (Change In The Operating Partnership's Unsecured Debt Ratings) (Details) | 9 Months Ended |
|---|---|
Sep. 30, 2011 | |
No Ratings Or Less Than BBB-/Baa3 [Member] | |
| Unsecured Debt Ratings | No ratings or less than BBB-/Baa3 |
| Interest Rate - Applicable Basis Points Above LIBOR | 185.0 |
| Facility Fee Basis Points | 45.0 |
BBB- Or Baa3 [Member] | |
| Unsecured Debt Ratings | BBB- or Baa3 |
| Interest Rate - Applicable Basis Points Above LIBOR | 150.0 |
| Facility Fee Basis Points | 35.0 |
BBB Or Baa2 (Current) [Member] | |
| Unsecured Debt Ratings | BBB or Baa2(current) |
| Interest Rate - Applicable Basis Points Above LIBOR | 125.0 |
| Facility Fee Basis Points | 25.0 |
BBB+ Or Baa1 [Member] | |
| Unsecured Debt Ratings | BBB+or Baa1 |
| Interest Rate - Applicable Basis Points Above LIBOR | 107.5 |
| Facility Fee Basis Points | 20.0 |
A- Or A3 Or Higher [Member] | |
| Unsecured Debt Ratings | A-or A3 or higher |
| Interest Rate - Applicable Basis Points Above LIBOR | 100.0 |
| Facility Fee Basis Points | 17.5 |