Annual report pursuant to Section 13 and 15(d)

Trading Securities (Schedule Of Fair Value Of Assets Measured On Recurring Basis) (Details)

v3.19.1
Trading Securities (Schedule Of Fair Value Of Assets Measured On Recurring Basis) (Details) - USD ($)
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading securities $ 4,000  
Fair Value [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading securities 4,000 $ 48,000
Money market funds 1,196 36,000
Total 5,196 84,000
Fair Value Measurements At Reporting Date Using Quoted Prices in Active Markets (Level 1) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading securities 4,000 48,000
Money market funds 1,196 36,000
Total 5,196 84,000
Fair Value Measurements At Reporting Date Using Significant Other Observable Inputs (Level 2) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading securities
Money market funds
Total
Fair Value Measurements At Reporting Date Using Significant Unobservable Inputs (Level 3) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading securities
Money market funds
Total