Long-Term Debt (Schedule of Long-Term Debt) (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Total debt
Long-term Debt, Total	$ 0	$ 10,000,000
Long-term debt, noncurrent		10,000,000
Revolving Credit Facility [Member]
Total debt
Long-term Debt, Total		10,000,000
Amounts payable within one year	$ 0	$ 0