Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 117,092,602	$ 111,897,852	$ 204,224,370	$ 325,136,888
Other comprehensive income before tax:
Foreign currency translation adjustments	1,823,667	(1,623,102)	1,268,204	(1,799,789)
Unrealized (losses) gains on debt securities, net	(146,647)	457,438	5,655,644	3,338,762
Other comprehensive income (loss), before tax	1,677,020	(1,165,664)	6,923,848	1,538,973
Income tax impact related to components of other comprehensive income	(30,796)	96,062	1,187,685	701,140
Other comprehensive income (loss), net of tax	1,707,816	(1,261,726)	5,736,163	837,833
Comprehensive Income	$ 118,800,418	$ 110,636,126	$ 209,960,533	$ 325,974,721