Annual report pursuant to Section 13 and 15(d)

Unsecured Revolving Credit Facility And Term Loans (Schedule Of Interest Rates On Outstanding Borrowings, Alternate Base Rate Loans, And Facility Fee) (Details)

v3.10.0.1
Unsecured Revolving Credit Facility And Term Loans (Schedule Of Interest Rates On Outstanding Borrowings, Alternate Base Rate Loans, And Facility Fee) (Details) - 2017 Credit Facility [Member]
 12 Months Ended
Dec. 31, 2018
Line of Credit Facility [Line Items]  
Facility Fee Basis Points 0.25%
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 1.55%
Facility Fee Basis Points 0.30%
Baa3 [Member] | BBB- [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB- or Baa3 (interest rate based on Company's election through March 5, 2018)
Interest Rate - Applicable Basis Points Above LIBOR 1.20%
Facility Fee Basis Points 0.25%
Baa2 [Member] | BBB [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB or Baa2
Interest Rate - Applicable Basis Points Above LIBOR 1.00%
Facility Fee Basis Points 0.20%
Baa1 [Member] | BBB+ [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB+ or Baa1
Interest Rate - Applicable Basis Points Above LIBOR 0.90%
Facility Fee Basis Points 0.15%
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 0.875%
Facility Fee Basis Points 0.125%
Base Rate [Member] | No Ratings Or Less Than Baa3 [Member] | No Ratings Or Less Than BBB- [Member]  
Line of Credit Facility [Line Items]  
Interest Rate - Applicable Basis Points Above LIBOR 0.55%
Base Rate [Member] | Baa3 [Member] | BBB- [Member]  
Line of Credit Facility [Line Items]  
Interest Rate - Applicable Basis Points Above LIBOR 0.20%
Base Rate [Member] | Baa2 [Member] | BBB [Member]  
Line of Credit Facility [Line Items]  
Interest Rate - Applicable Basis Points Above LIBOR 0.00%
Base Rate [Member] | Baa1 [Member] | BBB+ [Member]  
Line of Credit Facility [Line Items]  
Interest Rate - Applicable Basis Points Above LIBOR 0.00%
Base Rate [Member] | A3 Or Higher [Member] | A- Or Higher [Member]  
Line of Credit Facility [Line Items]  
Interest Rate - Applicable Basis Points Above LIBOR 0.00%