Summary of Significant Accounting Policies (Accumulated Other Comprehensive Earnings (Loss)) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net current period other comprehensive loss	$ (2,226,522)	$ (1,710,846)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Including Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	5,520,091	2,953,936
Other comprehensive loss before reclassification	(2,225,503)	(1,526,960)
Amount reclassified from accumulated other comprehensive loss	(1,019)	(183,886)
Net current period other comprehensive loss	(2,226,522)	(1,710,846)
Balance	$ 3,293,569	$ 1,243,090