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Other trading assets include assets that are carried on the balance sheet at fair value and held for trading purposes. A debt security represents a creditor relationship with an enterprise that is in the form of a security. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities (and other trading assets).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 3, 19, 20, 21, 22, 137 falsefalseInvestments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]3false0us-gaap_TradingSecuritiesRealizedGainus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse3000000.3falsetruefalsetruefalse3truefalsefalse38000003.8falsetruefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalse6falsefalsefalse00falsefalsefalsetruefalse7truefalsefalse36000003.6falsetruefalsetruefalse8falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the gain realized during the period from the sale of trading securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph c -Article 5 falsefalseTrading Securities, Realized Gain4false0us-gaap_TradingSecuritiesRealizedLossus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4truefalsefalse35000003.5falsefalsefalsetruefalse5truefalsefalse3000000.3falsefalsefalsetruefalse6truefalsefalse39000003.9falsefalsefalsetruefalse7falsefalsefalse00falsefalsefalsetruefalse8falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the loss realized during the period from the sale of trading securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph c -Article 5 falsefalseTrading Securities, Realized Loss5false0us-gaap_TradingSecuritiesUnrealizedHoldingLossus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalse6falsefalsefalse00falsefalsefalsetruefalse7falsefalsefalse00falsefalsefalsetruefalse8truefalsefalse20000002.0falsetruefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryFor trading securities held as of the balance sheet date, this amount represents the excess carrying value of trading securities over their fair value (unrealized holding loss). Trading securities are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) and such unrealized holding loss is included in earnings for the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 13 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 12 -Subparagraph a Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 21 -Subparagraph e falsefalseTrading Securities, Unrealized Holding Loss84Note 8 - Investment Securities (Detail) (USD $)HundredThousandsUnKnownUnKnownUnKnownfalsetrue