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Summary of Significant Accounting and Reporting Policies (Schedule of Assets or Liabilities Having Recurring Measurements) (Details) - USD ($) | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash & Cash Equivalents | $ 217,025,278 | $ 569,734,496
Total | 520,567,359 | 776,854,969
Certificates of Deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 150,299,384 | 130,000,000
Corporate Bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 6,967,700 | 12,944,999
Long-Term Investments | 60,369,930 | 3,018,720
Government Securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 9,176,227 | 9,011,130
Long-Term Investments | 56,483,720 | 0
Common Stocks |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments |  | 15,703,371
Municipal Bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments | 18,025,432 |
Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 2,219,688 | 188,344
Mutual Funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 393,581
Long-Term Investments |  | 34,681,337
Preferred Stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments |  | 1,178,991
Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash & Cash Equivalents | 217,025,278 | 569,734,496
Total | 369,544,350 | 751,486,539
Level 1 | Certificates of Deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 150,299,384 | 130,000,000
Level 1 | Corporate Bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Long-Term Investments | 0 | 0
Level 1 | Government Securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Long-Term Investments | 0 | 0
Level 1 | Common Stocks |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments |  | 15,703,371
Level 1 | Municipal Bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments | 0 |
Level 1 | Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 2,219,688 | 188,344
Level 1 | Mutual Funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Long-Term Investments |  | 34,681,337
Level 1 | Preferred Stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments |  | 1,178,991
Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash & Cash Equivalents | 0 | 0
Total | 151,023,009 | 25,368,430
Level 2 | Certificates of Deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Level 2 | Corporate Bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 6,967,700 | 12,944,999
Long-Term Investments | 60,369,930 | 3,018,720
Level 2 | Government Securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 9,176,227 | 9,011,130
Long-Term Investments | 56,483,720 | 0
Level 2 | Common Stocks |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments |  | 0
Level 2 | Municipal Bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments | 18,025,432 |
Level 2 | Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Level 2 | Mutual Funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 393,581
Long-Term Investments |  | 0
Level 2 | Preferred Stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments |  | 0
Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash & Cash Equivalents | 0 | 0
Level 3 | Certificates of Deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Level 3 | Corporate Bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Long-Term Investments | 0 | 0
Level 3 | Government Securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Long-Term Investments | 0 | 0
Level 3 | Common Stocks |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments |  | 0
Level 3 | Municipal Bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments | 0 |
Level 3 | Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | 0 | 0
Level 3 | Mutual Funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Short-Term Investments | $ 0 | 0
Long-Term Investments |  | 0
Level 3 | Preferred Stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Long-Term Investments |  | $ 0

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