Comprehensive Income (AOCI Rollforward) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022		Mar. 31, 2021	Dec. 31, 2021	[1]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 1,937,988,467	[1]	$ 1,963,943,128
Net current-period change	(7,054,652)		(4,896,385)
Balance at end of period	1,928,968,900		1,960,980,714
Accumulated other comprehensive (loss) income, end of period	(5,127,408)			$ 1,927,244
Accumulated  Other Comprehensive (Loss) Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	1,927,244		6,851,052
Net current-period change	(7,054,652)		(4,896,385)
Balance at end of period	(5,127,408)		1,954,667
Accumulated other comprehensive (loss) income, end of period	(5,127,408)		1,954,667
Foreign currency translation adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	920,589		769,045
Other Comprehensive loss before reclassifications	(896,420)		(852,412)
Net current-period change	(896,420)		(852,412)
Balance at end of period	24,169		(83,367)
Unrealized gains on available-for-sale debt securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	1,006,655		6,082,007
Other Comprehensive loss before reclassifications	(6,423,937)		(3,692,619)
Amounts reclassified from accumulated other comprehensive income	265,705		(351,354)
Net current-period change	(6,158,232)		(4,043,973)
Balance at end of period	$ (5,151,577)		$ 2,038,034

[1] The condensed consolidated balance sheet at December 31, 2021 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.