Organization And Summary Of Significant Accounting Policies (Schedule Of Changes In Reserve) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Organization And Summary Of Significant Accounting Policies Schedule Of Changes In Reserve
Balance at beginning of the year	$ 77,102	$ 263,092
Accrued allowances
Reclassification of allowance from accounts receivable to accounts payable and accrued liabilities		173,426
Expenditures		12,564
Balance at year-end	$ 77,102	$ 77,102