Unsecured Revolving Credit Facility (Schedule Of Unsecured Credit Rating And Facility Fee) (Details)
 9 Months Ended
Sep. 30, 2016
No Ratings Or Less Than Baa3 [Member] | No Ratings Or Less Than BBB- [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings No ratings or less than BBB-/Baa3
Baa3 [Member] | BBB- [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB- or Baa3 (current interest rate based on Company's election)
Baa2 [Member] | BBB [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB or Baa2
Baa1 [Member] | BBB+ [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB+ or Baa1
A3 Or Higher [Member] | A- Or Higher [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings A- or A3 or higher
Unsecured Revolving Credit Facility [Member] | No Ratings Or Less Than Baa3 [Member] | No Ratings Or Less Than BBB- [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings No ratings or less than BBB-/Baa3
Interest Rate - Applicable Basis Points Above LIBOR 1.70%
Facility Fee Basis Points 0.35%
Unsecured Revolving Credit Facility [Member] | Baa3 [Member] | BBB- [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB- or Baa3 (current)
Interest Rate - Applicable Basis Points Above LIBOR 1.30%
Facility Fee Basis Points 0.30%
Unsecured Revolving Credit Facility [Member] | Baa2 [Member] | BBB [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB or Baa2
Interest Rate - Applicable Basis Points Above LIBOR 1.10%
Facility Fee Basis Points 0.20%
Unsecured Revolving Credit Facility [Member] | Baa1 [Member] | BBB+ [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB+ or Baa1
Interest Rate - Applicable Basis Points Above LIBOR 1.00%
Facility Fee Basis Points 0.15%
Unsecured Revolving Credit Facility [Member] | A3 Or Higher [Member] | A- Or Higher [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings A- or A3 or higher
Interest Rate - Applicable Basis Points Above LIBOR 0.925%
Facility Fee Basis Points 0.125%