Accrued Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Accrued Liabilities
Payroll and related items	$ 383,000	$ 370,000
Real estate taxes	962,000	972,000
Pension	1,146,000	1,150,000
Other	592,000	557,000
Total	$ 3,083,000	$ 3,049,000