Investments (Details 4)	3 Months Ended
	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)
Investments:
Sold securities - number	1	1
Sold securities - amortized cost	$ 249,995	$ 601,316
Sold securities - realized gain (loss)	$ 2	$ 1,114
Called securities - number	2	0
Called securities - amortized cost	$ 1,374,901	$ 0
Called securities - realized gain (loss)	$ 99	$ 0