Investments, Debt Securities by Contractual Maturity (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Amortized cost [Abstract]
Due in one year or less	$ 2,500,083
Due after one year through five years	62,005,611
Due after five years through ten years	50,915,439
Due after ten years	47,870,755
Original or amortized cost	163,291,888	$ 160,895,869
Fair value [Abstract]
Due in one year or less	2,499,750
Due after one year through five years	64,052,446
Due after five years through ten years	56,800,689
Due after ten years	52,649,566
Fair value	$ 176,002,451	$ 160,960,784	[1]

[1] Balance sheet audited at December 31, 2018.