Investments (Tables)

3 Months Ended

Mar. 31, 2016

Investments [Abstract]

Investment Securities Stated at Fair Value

Assets or liabilities that have recurring fair value measurements are shown below as of March 31, 2016, and December 31, 2015:

As of March 31, 2016:

			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, 2016		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	626,470,720	$	626,470,720	$	—	$	—
Short-Term Investments:
Government Securities	3,010,680		—		3,010,680		—
Mutual Funds	5,053,198		—		5,053,198		—
Corporate Bonds	1,501,335		—		1,501,335		—
Other	30,049		30,049		—		—
Long-Term Investments:
Common Stocks	17,069,251		17,069,251		—		—
Mutual Funds – Equity	53,994,481		53,994,481		—		—
Total	$	707,129,714	$	697,564,501	$	9,565,213	$	—

As of December 31, 2015:

			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, 2015		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	551,557,527	$	551,557,527	$	—	$	—
Short-Term Investments:
Government Securities	3,010,860		—		3,010,860		—
Corporate Bonds	1,512,015		—		1,512,015		—
Other	24,480		24,480		—		—
Long-Term Investments:
Common Stocks	20,454,804		20,454,804		—		—
Mutual Funds – Equity	74,701,735		74,701,735		—		—
Total	$	651,261,421	$	646,738,546	$	4,522,875	$	—

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, 2016, and December 31, 2015:

As of March 31, 2016:

			Unrealized
	Cost		Gains		Losses			Market Value
Short-Term Investments:
Government Securities	$	3,008,955	$	1,725	$	—		$	3,010,680
Mutual Funds	4,997,416		55,782		—			5,053,198
Corporate Bonds	1,501,654		—		(319		)	1,501,335
Other	30,049		—		—			30,049
Long-Term Investments:
Common Stocks	14,168,958		3,716,147		(815,854		)	17,069,251
Mutual Funds – Equity	55,994,531		1,246,254		(3,246,304		)	53,994,481
Other – Equity	—		—		—			—
Total	$	79,701,563	$	5,019,908	$	(4,062,477	)	$	80,658,994

As of December 31, 2015:

			Unrealized
	Cost		Gains		Losses			Market Value
Short-Term Investments:
Government Securities	$	3,013,482	$	—	$	(2,622	)	$	3,010,860
Corporate Bonds	1,512,405		—		(390		)	1,512,015
Other	24,480		—		—			24,480
Long-Term Investments:
Common Stocks	17,395,641		4,078,912		(1,019,749		)	20,454,804
Mutual Funds – Equity	76,481,106		2,067,399		(3,846,770		)	74,701,735
Total	$	98,427,114	$	6,146,311	$	(4,869,531	)	$	99,703,894

Schedule of Unrealized Loss on Investments

Unrealized losses on investments as of March 31, 2016, are as follows:

	Aggregate Unrealized Losses		Aggregate Fair Value
Less than one year	$	3,946,332	$	43,246,027
Greater than one year	116,145		248,850
Total	$	4,062,477	$	43,494,877

Unrealized losses on investments as of December 31, 2015, are as follows:

	Aggregate Unrealized Losses		Aggregate Fair Value
Less than one year	$	4,869,531	$	65,440,181