Annual report pursuant to Section 13 and 15(d)

Unsecured Revolving Credit Facility (Change In The Operating Partnership's Unsecured Debt Ratings) (Details)

v2.4.0.6
Unsecured Revolving Credit Facility (Change In The Operating Partnership's Unsecured Debt Ratings) (Details)
12 Months Ended
Dec. 31, 2012
No Ratings Or Less Than BBB-/Baa3 [Member]
 
Guarantor Obligations [Line Items]  
Unsecured Debt Ratings No ratings or less than BBB-/Baa3
Interest Rate - Applicable Basis Points Above LIBOR 1.85%
Facility Fee Basis Points 0.45%
BBB- Or Baa3 [Member]
 
Guarantor Obligations [Line Items]  
Unsecured Debt Ratings BBB- or Baa3
Interest Rate - Applicable Basis Points Above LIBOR 1.50%
Facility Fee Basis Points 0.35%
BBB Or Baa2 (Current) [Member]
 
Guarantor Obligations [Line Items]  
Unsecured Debt Ratings BBB or Baa2(current)
Interest Rate - Applicable Basis Points Above LIBOR 1.25%
Facility Fee Basis Points 0.25%
BBB+ Or Baa1 [Member]
 
Guarantor Obligations [Line Items]  
Unsecured Debt Ratings BBB+or Baa1
Interest Rate - Applicable Basis Points Above LIBOR 1.075%
Facility Fee Basis Points 0.20%
A- Or A3 Or Higher [Member]
 
Guarantor Obligations [Line Items]  
Unsecured Debt Ratings A-or A3 or higher
Interest Rate - Applicable Basis Points Above LIBOR 1.00%
Facility Fee Basis Points 0.175%