Investments (Tables)

6 Months Ended

Jun. 30, 2013

Investments [Abstract]

Investment Securities Stated at Fair Value

Assets or liabilities that have recurring measurements are shown below as of June 30, 2013, and December 31, 2012:

			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, 2013		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	502,721,765	$	502,721,765			$	—
Short-Term Investments:
Certificate of Deposit	260,881		—		260,881		—
Government Securities	53,062,359		—		53,062,359		—
U.S. Treasury Notes	28,279,240		—		28,279,240		—
Corporate Bonds	10,493,359		—		10,493,359		—
Other	420,413		420,413		—		—
Long-Term Investments:
Corporate Bonds	—		—		—		—
U.S. Treasury Notes	—		—		—		—
Common Stocks	46,475,420		46,475,420		—		—
Mutual Funds – Equity	90,502,508		90,502,508		—		—
Total	$	732,215,945	$	640,120,106	$	92,095,839	$	—

			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, 2012		(Level 1)		(Level 2)		(Level 3)
Cash & Cash Equivalents	$	389,678,664	$	389,678,664	$	—	$	—
Short-Term Investments:
Certificate of Deposit	510,881		—		510,881		—
Government Securities	38,522,471		—		38,522,471		—
U.S. Treasury Notes	15,020,350		—		15,020,350		—
Corporate Bonds	6,563,228		—		6,563,228		—
Other	185,926		185,926		—		—
Long-Term Investments:
Corporate Bonds	2,180,780		—		2,180,780		—
Common Stocks	53,283,201		53,283,201		—		—
Mutual Funds – Equity	86,109,053		86,109,053		—		—
Other – Equity	261,000		261,000		—		—
Total	$	592,315,554	$	529,517,844	$	62,797,710	$	—

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, 2013, and December 31, 2012:

As of June 30, 2013:

			Unrealized
	Cost		Gains		Losses			Market Value
Short-Term Investments:
Certificate of Deposit	$	260,881	$	—	$	—		$	260,881
Government Securities	53,065,141		6,139		(8,921		)	53,062,359
U.S. Treasury Notes	28,274,980		5,971		(1,711		)	28,279,240
Corporate Bonds	10,484,488		10,351		(1,480		)	10,493,359
Other	420,413							420,413
Long-Term Investments:
Corporate Bonds	—		—		—			—
U.S. Treasury Notes	—		—		—			—
Common Stocks	34,990,852		11,684,312		(199,744		)	46,475,420
Mutual Funds – Equity	73,228,014		17,313,612		(39,118		)	90,502,508
Total	$	200,724,769	$	29,020,385	$	(250,974	)	$	229,494,180

As of December 31, 2012:

			Unrealized
	Cost		Gains		Losses			Market Value
Short-Term Investments:
Certificate of Deposit	$	510,881	$	—	$	—		$	510,881
Government Securities	38,514,411		9,004		(944		)	38,522,471
U.S. Treasury Notes	15,018,810		2,602		(1,062		)	15,020,350
Corporate Bonds	6,529,758		33,470		—			6,563,228
Other	185,926		—		—			185,926
Long-Term Investments:
Corporate Bonds	2,174,948		5,832		—			2,180,780
Common Stocks	40,893,121		12,781,501		(391,421		)	53,283,201
Mutual Funds – Equity	75,321,640		11,082,714		(295,301		)	86,109,053
Other – Equity	238,506		22,494		—			261,000
Total	$	179,388,001	$	23,937,617	$	(688,728	)	$	202,636,890

Schedule of Unrealized Loss on Investments

Unrealized losses on investments as of June 30, 2013, are as follows:

	Aggregate Unrealized Losses		Aggregate Fair Value
Less than one year	$	250,974	$	40,309,073

Unrealized losses on investments as of December 31, 2012, are as follows:

	Aggregate Unrealized Losses		Aggregate Fair Value
Less than one year	$	688,728	$	22,887,686

Maturities of Fixed Income Securities

Fixed income securities as of June 30, 2013, have contractual maturities as follows:

Due within one year	$	92,095,839
Due between one and five years	—
Total	$	92,095,839