Investments (Schedule of Amortized Cost, Unrealized Gains And Losses, And Market Value of Investment Securities) (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cash & Cash Equivalents	$ 391,650,469	$ 309,591,724
Cost	86,193,927	77,055,612
Unrealized Gains	23,889,220	29,998,513
Unrealized Losses	(285,296)	(48,603)
Investments	109,797,851	107,005,522
Investments and Cash	501,448,320	416,597,246
Short-term Investments [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	65
Unrealized Gains	0
Unrealized Losses	0
Investments	65
Long-Term Investments [Member] | Common Stocks
Schedule of Available-for-sale Securities [Line Items]
Cost	15,871,777	22,799,035
Unrealized Gains	8,399,886	10,532,007
Unrealized Losses	(284,260)	(48,603)
Investments	23,987,403	33,282,439
Long-Term Investments [Member] | Mutual Funds – Equity
Schedule of Available-for-sale Securities [Line Items]
Cost	70,322,085	54,256,577
Unrealized Gains	15,489,334	19,466,506
Unrealized Losses	(1,036)	0
Investments	85,810,383	73,723,083
Fair Value, Inputs, Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash & Cash Equivalents	391,650,469	309,591,724
Investments and Cash	501,448,320	416,597,246
Fair Value, Inputs, Level 1 [Member] | Short-term Investments [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments	65
Fair Value, Inputs, Level 1 [Member] | Long-Term Investments [Member] | Common Stocks
Schedule of Available-for-sale Securities [Line Items]
Investments	23,987,403	33,282,439
Fair Value, Inputs, Level 1 [Member] | Long-Term Investments [Member] | Mutual Funds – Equity
Schedule of Available-for-sale Securities [Line Items]
Investments	85,810,383	73,723,083
Fair Value, Inputs, Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash & Cash Equivalents	0	0
Investments and Cash	0	0
Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments	0
Fair Value, Inputs, Level 2 [Member] | Long-Term Investments [Member] | Common Stocks
Schedule of Available-for-sale Securities [Line Items]
Investments	0	0
Fair Value, Inputs, Level 2 [Member] | Long-Term Investments [Member] | Mutual Funds – Equity
Schedule of Available-for-sale Securities [Line Items]
Investments	0	0
Fair Value, Inputs, Level 3 [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash & Cash Equivalents	0	0
Investments and Cash	0	0
Fair Value, Inputs, Level 3 [Member] | Short-term Investments [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments	0
Fair Value, Inputs, Level 3 [Member] | Long-Term Investments [Member] | Common Stocks
Schedule of Available-for-sale Securities [Line Items]
Investments	0	0
Fair Value, Inputs, Level 3 [Member] | Long-Term Investments [Member] | Mutual Funds – Equity
Schedule of Available-for-sale Securities [Line Items]
Investments	$ 0	$ 0