Summary Of Significant Accounting And Reporting Policies (Schedule Of Assets Or Liabilities Having Recurring Measurements) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	$ 389,678,664	$ 357,986,774
Total	592,315,554	546,963,176
Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	38,522,471	35,024,030
U.S. Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	15,020,350	25,044,000
Corporate Bond [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	6,563,228	649,204
Long-term Investments, Fair Value Disclosure	2,180,780
Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	185,926	91,003
Common Stocks [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	53,283,201	53,554,303
Mutual Funds - Equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	86,109,053	73,749,772
Certificate Of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	510,881
Long-term Investments, Fair Value Disclosure		505,390
Other - Equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	261,000	358,700
Fair Value, Assets, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	389,678,664	357,986,774
Total	529,517,844	485,740,552
Fair Value, Assets, Level 1 [Member] | Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0	0
Fair Value, Assets, Level 1 [Member] | U.S. Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0	0
Fair Value, Assets, Level 1 [Member] | Corporate Bond [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0	0
Long-term Investments, Fair Value Disclosure	0
Fair Value, Assets, Level 1 [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	185,926	91,003
Fair Value, Assets, Level 1 [Member] | Common Stocks [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	53,283,201	53,554,303
Fair Value, Assets, Level 1 [Member] | Mutual Funds - Equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	86,109,053	73,749,772
Fair Value, Assets, Level 1 [Member] | Certificate Of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0
Long-term Investments, Fair Value Disclosure		0
Fair Value, Assets, Level 1 [Member] | Other - Equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	261,000	358,700
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	0	0
Total	62,797,710	61,222,624
Fair Value, Inputs, Level 2 [Member] | Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	38,522,471	35,024,030
Fair Value, Inputs, Level 2 [Member] | U.S. Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	15,020,350	25,044,000
Fair Value, Inputs, Level 2 [Member] | Corporate Bond [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	6,563,228	649,204
Long-term Investments, Fair Value Disclosure	2,180,780
Fair Value, Inputs, Level 2 [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] | Common Stocks [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] | Mutual Funds - Equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] | Certificate Of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	510,881
Long-term Investments, Fair Value Disclosure		505,390
Fair Value, Inputs, Level 2 [Member] | Other - Equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	0	0
Total
Fair Value, Inputs, Level 3 [Member] | Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | U.S. Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Corporate Bond [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0	0
Long-term Investments, Fair Value Disclosure	0
Fair Value, Inputs, Level 3 [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Common Stocks [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Mutual Funds - Equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Certificate Of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments, Fair Value Disclosure	0
Long-term Investments, Fair Value Disclosure		0
Fair Value, Inputs, Level 3 [Member] | Other - Equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Investments, Fair Value Disclosure	$ 0	$ 0