Line of Credit and Long-Term Debt - Additional Information (Details)	1 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($)	Sep. 30, 2020 USD ($) covenant	Dec. 31, 2013 USD ($)	Dec. 31, 2019 USD ($)	Aug. 31, 2019 USD ($)
Line of Credit Facility [Line Items]
Interest pay rate					4.16%
Promissory note agreement
Line of Credit Facility [Line Items]
Long-term debt		$ 2,250,000
Debt instrument face amount			$ 4,750,000
Stated interest rate			4.25%
Periodic principal and interest payments			$ 36,000
Additional payment	$ 687,000
Principal monthly payments		28,000
Term Notes
Line of Credit Facility [Line Items]
Long-term debt		$ 55,879,000		$ 58,768,000
Term Notes | Selected LIBOR rate
Line of Credit Facility [Line Items]
Interest rate on line of credit, variable rate		1.70%
Revolving line of credit
Line of Credit Facility [Line Items]
Line of credit amount		$ 35,000,000			$ 30,000,000
RLC outstanding balance		$ 0		$ 0
Number of debt covenants | covenant		3
Debt equity ratio		0.75
Debt service coverage ratio		1.25
Minimum liquid assets		$ 20,000,000
Commitment fee percentage		0.10%
Revolving line of credit | Selected LIBOR rate
Line of Credit Facility [Line Items]
Interest rate on line of credit, variable rate		1.50%
Revolving line of credit | LIBOR for a fixed rate term
Line of Credit Facility [Line Items]
Interest rate on line of credit, variable rate		1.50%