Investments (Tables)

6 Months Ended

Jun. 30, 2021

Investments [Abstract]

Investment Securities Stated at Fair Value

Assets or liabilities that have recurring fair value measurements are shown below as of June 30, 2021 and December 31, 2020:

As of June 30, 2021:

			Fair Value Measurements at Reporting Date Using
	Total as of		Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
Description	June 30, 2021		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	353,032,803	$	353,032,803	$	—	$	—
Short-Term Investments:
Certificate of Deposit	1,511,377		1,511,377		—		—
Corporate Bonds	2,020,280		—		2,020,280		—
Government Securities	602,016		—		602,016		—
Municipal Bonds	7,951,512		—		7,951,512		—
Other	1,713,642		1,713,642		—		—
Long-Term Investments:
Asset Backed Securities	29,174,900		—		29,174,900		—
Certificate of Deposit	2,599,960		2,599,960		—		—
Corporate Bonds	27,966,498		—		27,966,498		—
Government Securities	35,738,826		—		35,738,826		—
Municipal Bonds	88,934,125		—		88,934,125		—
Total	$	551,245,939	$	358,857,782	$	192,388,157	$	—

As of December 31, 2020:

			Fair Value Measurements at Reporting Date Using
	Total as of		Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
Description	December 31, 2020		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	423,371,036	$	423,371,036	$	—	$	—
Short-Term Investments:
Certificate of Deposit	1,516,693		1,516,693		—		—
Corporate Bonds	7,155,600		—		7,155,600		—
Government Securities	6,678,450		—		6,678,450		—
Municipal Bonds	10,284,765		—		10,284,765		—
Other	1,528,861		1,528,861		—		—
Long-Term Investments:
Asset-backed Securities	37,924,537		—		37,924,537		—
Certificate of Deposit	3,645,520		3,645,520				—
Corporate Bonds	9,024,035		—		9,024,035		—
Municipal Bonds	107,407,831		—		107,407,831		—
Total	$	608,537,328	$	430,062,110	$	178,475,218	$	—

Schedule of Amortized Cost, Unrealized Gains And Losses, And Market Value of Investment Securities

The amortized cost, unrealized gains and losses, and market value of investment securities are shown as of June 30, 2021 and December 31, 2020:

As of June 30, 2021:

			Unrealized
	Cost		Gains		Losses		Market Value
Short-Term Investments:
Certificate of Deposit	$	1,502,822	$	10,107	$	(1,552)	$	1,511,377
Corporate Bonds	2,013,237		7,043		—		2,020,280
Government Securities	601,784		232		—		602,016
Municipal Bonds	7,926,891		24,621		—		7,951,512
Other	1,713,642		—		—		1,713,642
Long-Term Investments:
Asset Backed Securities	29,690,643		69,718		(585,461)		29,174,900
Certificate of Deposit	2,502,449		97,511		—		2,599,960
Corporate Bonds	27,724,234		362,001		(119,737)		27,966,498
Government Securities	35,656,412		90,333		(7,919)		35,738,826
Municipal Bonds	84,595,949		6,309,593		(1,971,417)		88,934,125
Total	$	193,928,063	$	6,971,159	$	(2,686,086)	$	198,213,136

As of December 31, 2020:    

			Unrealized
	Cost		Gains		Losses		Market Value
Short-Term Investments:
Certificate of Deposit	$	1,502,187	$	14,506	$	—	$	1,516,693
Corporate Bonds	7,084,638		70,962		—		7,155,600
Government Securities	6,635,132		43,318		—		6,678,450
Municipal Bonds	10,160,376		124,389		—		10,284,765
Other	1,528,861		—		—		1,528,861
Long-Term Investments:
Asset-backed Securities	37,681,113		800,802		(557,378)		37,924,537
Certificate of Deposit	3,503,898		141,622		—		3,645,520
Corporate Bonds	8,595,020		429,015		—		9,024,035
Municipal Bonds	100,776,325		6,635,428		(3,922)		107,407,831
Total	$	177,467,550	$	8,260,042	$	(561,300)	$	185,166,292

Schedule of Unrealized Loss on Investments

Unrealized losses on investments as of June 30, 2021, are as follows:

	Aggregate Unrealized Losses		Aggregate Fair Value of Investments
Loss duration of less than one year	$	2,274,743	$	40,341,064
Loss duration of greater than one year	411,342		1,956,482
Total	$	2,686,085	$	42,297,546

Unrealized losses on investments as of December 31, 2020, are as follows:

	Aggregate Unrealized Losses		Aggregate Fair Value of Investments
Loss duration of less than one year	$	561,300	$	12,317,187
Loss duration of greater than one year	—		—
Total	$	561,300	$	12,317,187

Investments Classified by Contractual Maturity Date

Fixed income securities as of June 30, 2021 have contractual maturities as follows:

Due within one year	$	12,085,185
Due between one and five years	42,578,597
Due over five years	141,835,712
	$	196,499,494