Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 76,660,548	$ 117,092,602	$ 276,617,836	$ 204,224,370
Other comprehensive income (loss) before tax:
Foreign currency translation adjustments	(349,165)	1,823,667	(238,378)	1,268,204
Unrealized (losses) gains on debt securities, net	(816,801)	(146,647)	(4,230,473)	5,655,644
Other comprehensive income (loss), before tax	(1,165,966)	1,677,020	(4,468,851)	6,923,848
Income tax impact related to components of other comprehensive income (loss)	(171,528)	(30,796)	(888,399)	1,187,685
Other comprehensive income (loss), net of tax	(994,438)	1,707,816	(3,580,452)	5,736,163
Comprehensive income	$ 75,666,110	$ 118,800,418	$ 273,037,384	$ 209,960,533