Accrued Expenses - Summarizes information related to accrued expense (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Accrued Expenses
Accrued expenses	$ 1,987,000	$ 2,085,000
Accrued interest	209,000	199,000
Accrued payroll	1,339,000	1,253,000
Accrued vacation and sick pay	631,000	496,000
Accrued shipping expenses	478,000	433,000
Accrued legal fees	541,000	192,000
Deferred rent liability	325,000	301,000
Total accrued expenses	$ 5,510,000	$ 4,959,000