Mortgage Loans On Real Estate (Schedule Of Mortgage Loans On Real Estate) (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2017
USD ($)
Mortgage Loans on Real Estate [Line Items]  
Face Amount of Mortgages or Maximum Available Credit $ 44,695
Carrying Amount of Mortgages $ 45,734
Borrower A [Member] | Land [Member]  
Mortgage Loans on Real Estate [Line Items]  
Interest Accrual Rate 5.85%
Interest Payment Rate 5.85%
Final Maturity Date Jul. 21, 2019
Periodic Payment Terms P&I
Face Amount of Mortgages or Maximum Available Credit $ 44,695
Carrying Amount of Mortgages $ 45,734