Pension and Profit Sharing - Periodic Benefit Cost (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assumptions used to determine net periodic benefit cost:
Discount rate		3.14%	3.40%
Expected return on plan assets		6.00%	6.00%
Components of net benefit expense:
Interest cost		$ 39,851	$ 48,161
Service cost	$ 543	33,000	36,000
Expected return on plan assets		(67,547)	(69,465)
Amortization of prior service costs		543	543
Amortization of actuarial loss		87,360	108,052
Net periodic benefit cost		$ 93,207	$ 123,291