XML 61 R47.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Note 8 - Investments, Including Investments Accounted for Using the Equity Method - Trading Securities (Details) - USD ($) | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2018 | Dec. 31, 2017
U.S. Treasury trading securities |  | $ 83,100,805
US Treasury Bill Securities [Member] |  |
Cost |  | 82,968,614
Gross unrealized gain |  | 132,191
U.S. Treasury trading securities |  | $ 83,100,805

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.4) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_TradingSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Cost of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading. + References No definition available. + Details
Name: | us-gaap_TradingSecuritiesCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrealized holding gain before loss recognized in the income statement for investments in trading securities. + References No definition available. + Details
Name: | us-gaap_TradingSecuritiesUnrealizedHoldingGain
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasuryBillSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |