Investments (Tables)

9 Months Ended

Sep. 30, 2020

Investments [Abstract]

Investment Securities Stated at Fair Value

Assets or liabilities that have recurring fair value measurements are shown below as of September 30, 2020 and December 31, 2019:

As of September 30, 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	September 30, 2020		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	400,499,542	$	400,499,542	$	—	$	—
Short-Term Investments:
Certificate of Deposit	1,270,465		1,270,465		—		—
Corporate Bonds	14,105,245		—		14,105,245		—
Government Securities	23,235,183		—		23,235,183		—
Municipal Bonds	11,025,844		—		11,025,844		—
Other	2,941,743		2,941,743		—		—
Long-Term Investments:
Asset Backed Securities	42,012,670		—		42,012,670		—
Certificate of Deposit	3,913,968		3,913,968		—		—
Corporate Bonds	8,975,930		—		8,975,930		—
Government Securities	—		—		—		—
Municipal Bonds	95,487,532		—		95,487,532		—
Total	$	603,468,122	$	408,625,718	$	194,842,404	$	—

As of December 31, 2019:

			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, 2019		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	296,321,622	$	296,321,622	$	—	$	—
Short-Term Investments:
Certificate of Deposit	50,099,795		50,099,795		—		—
Corporate Bonds	29,219,685		—		29,219,685		—
Government Securities	58,432,823		—		58,432,823		—
Other	2,631,750		2,631,750		—		—
Long-Term Investments:
Asset-backed Securities	25,791,029		—		25,791,029		—
Certificate of Deposit	3,557,798		3,557,798				—
Corporate Bonds	22,815,998		—		22,815,998		—
Governmental Securities	6,088,190		—		6,088,190		—
Municipal Bonds	72,638,690		—		72,638,690		—
Total	$	567,597,380	$	352,610,965	$	214,986,415	$	—

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 September 30, 2020 and December 31, 2019:

As of September 30, 2020:

			Unrealized
	Cost		Gains		Losses		Market Value
Short-Term Investments:
Certificate of Deposit	$	1,252,187	$	18,278	$	—	$	1,270,465
Corporate Bonds	13,970,360		134,885		—		14,105,245
Government Securities	23,105,527		129,656		—		23,235,183
Municipal Bonds	10,864,899		160,945		—		11,025,844
Other	2,941,743		—		—		2,941,743
Long-Term Investments:
Asset Backed Securities	41,521,603		1,086,633		(595,566)		42,012,670
Certificate of Deposit	3,754,312		159,656		—		3,913,968
Corporate Bonds	8,598,910		377,020		—		8,975,930
Municipal Bonds	89,916,703		5,580,670		(9,841)		95,487,532
Total	$	195,926,244	$	7,647,743	$	(605,407)	$	202,968,580

As of December 31, 2019:    

			Unrealized
	Cost		Gains		Losses		Market Value
Short-Term Investments:
Certificate of Deposit	$	50,099,795	$	—	$	—	$	50,099,795
Corporate Bonds	29,025,624		194,061		—		29,219,685
Government Securities	58,343,911		99,917		(11,005)		58,432,823
Other	2,631,750		—		—		2,631,750
Long-Term Investments:
Asset-backed Securities	25,971,156		—		(180,127)		25,791,029
Certificate of Deposit	3,500,000		58,808		(1,010)		3,557,798
Corporate Bonds	22,306,130		509,868		—		22,815,998
Government Securities	6,012,705		75,485		—		6,088,190
Municipal Bonds	71,997,996		1,036,116		(395,422)		72,638,690
Total	$	269,889,067	$	1,974,255	$	(587,564)	$	271,275,758

Schedule of Unrealized Loss on Investments

Unrealized losses on investments as of September 30, 2020, are as follows:

	Aggregate Unrealized Losses		Aggregate Fair Value
Loss duration of less than one year	$	605,407	$	24,572,356
Loss duration of greater than one year	—		—
Total	$	605,407	$	24,572,356

Unrealized losses on investments as of December 31, 2019, are as follows: 

	Aggregate Unrealized Losses		Aggregate Fair Value
Loss duration of less than one year	$	587,564	$	90,721,081
Loss duration of greater than one year	—		—
Total	$	587,564	$	90,721,081

Investments Classified by Contractual Maturity Date

Fixed income securities as of September 30, 2020 have contractual maturities as follows:

Due within one year	$	49,192,972
Due between one and five years	30,466,413
Due over five years	113,325,115
	$	192,984,500