Investments (Tables)

3 Months Ended

Mar. 31, 2020

Investments [Abstract]

Investment Securities Stated at Fair Value

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

As of March 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	March 31, 2020		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	278,524,928	$	278,524,928	$	—	$	—
Short-Term Investments:
Certificate of Deposit	50,099,795		50,099,795		—		—
Corporate Bonds	29,122,402		—		29,122,402		—
Government Securities	46,903,815		—		46,903,815		—
Municipal Bonds	2,084,121		—		2,084,121		—
Other	2,867,906		2,867,906		—		—
Long-Term Investments:
Asset Backed Securities	43,628,702		—		43,628,702		—
Certificate of Deposit	5,086,858		5,086,858		—		—
Corporate Bonds	20,397,525		—		20,397,525		—
Government Securities	7,308,584		—		7,308,584		—
Municipal Bonds	92,358,822		—		92,358,822		—
Total	$	578,383,458	$	336,579,487	$	241,803,971	$	—

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 March 31, 2020 and December 31, 2019:

As of March 31, 2020:

			Unrealized
	Cost		Gains		Losses		Market Value
Short-Term Investments:
Certificate of Deposit	$	50,099,795	$	—	$	—	$	50,099,795
Corporate Bonds	29,047,745		84,838		(10,181)		29,122,402
Government Securities	46,564,204		339,611		—		46,903,815
Municipal Bonds	2,079,998		4,123		—		2,084,121
Other	2,867,906		—		—		2,867,906
Long-Term Investments:
Asset Backed Securities	43,046,638		988,808		(406,744)		43,628,702
Certificate of Deposit	5,007,454		87,617		(8,213)		5,086,858
Corporate Bonds	20,271,904		330,691		(205,070)		20,397,525
Government Securities	7,150,365		158,219		—		7,308,584
Municipal Bonds	89,556,097		2,905,405		(102,680)		92,358,822
Total	$	295,692,106	$	4,899,312	$	(732,888)	$	299,858,530

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 March 31, 2020, are as follows:

	Aggregate Unrealized Losses		Aggregate Fair Value
Loss duration of less than one year	$	732,888	$	36,159,819
Loss duration of greater than one year	—		—
Total	$	732,888	$	36,159,819

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 March 31, 2020 have contractual maturities as follows:

Due within one year	$	128,210,132
Due between one and five years	52,232,126
Due over five years	116,548,364
	$	296,990,622