2.4.0.8152 - Disclosure - Fair Value of Financial Instruments (Details)truefalseIn Thousands, unless otherwise specifiedfalse1false USDfalsefalse$PAsOn06_30_2013http://www.sec.gov/CIK0001287701instant2013-06-30T00:00:000001-01-01T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$PAsOn12_31_2012http://www.sec.gov/CIK0001287701instant2012-12-31T00:00:000001-01-01T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 4us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Financial assets:2false 5gkk_LendingInvestmentsCarryingValuegkk_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse00[1],[2]USD$falsetruefalse2truefalsefalse784135000784135[1],[2]USD$falsetruefalsexbrli:monetaryItemTypemonetaryCarrying value of lending investments.No definition available.false2Lending Investments Carrying Value3false 5gkk_LendingInvestmentsFairValuegkk_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse00[1],[2]falsefalsefalse2truefalsefalse816283000816283[1],[2]falsefalsefalsexbrli:monetaryItemTypemonetaryFair value of lending investments.No definition available.false2Lending investments, Fair Value4false 5us-gaap_AvailableForSaleSecuritiesus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse00[2]falsefalsefalse2truefalsefalse932265000932265[2]falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 false2CMBS, Carrying Value5false 5gkk_AvailableForSaleSecuritiesFairValuegkk_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse00[2]falsefalsefalse2truefalsefalse932265000932265[2]falsefalsefalsexbrli:monetaryItemTypemonetaryFair value of investment in debt and equity securities categorized neither as held-to-maturity nor trading.No definition available.false2CMBS, Fair Value6false 5us-gaap_DerivativeAssetsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalsedefinitionGuidance1truefalsefalse00[2]falsefalsefalse2truefalsefalse173000173[2]falsefalsefalsexbrli:monetaryItemTypemonetaryFair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. 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Includes assets not subject to a master netting arrangement and not elected to be offset.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13433-108611 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13495-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=20225523&loc=SL20225862-175312 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=28370219&loc=SL20226008-175313 false2Derivative instruments, Fair Value8false 5gkk_RetainedCollateralizedDebtObligationsBondsCarringValuegkk_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse76450007645[3]falsefalsefalse2truefalsefalse00[3]falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying value of the retained collateralized debt obligations bonds.No definition available.false2Retained CDO Bonds, Carring Value9false 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available.false2Collateralized debt obligations, Carrying Value12false 5gkk_CollateralizedDebtObligationsFairValueDisclosuregkk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse00[1],[2]falsefalsefalse2truefalsefalse14742360001474236[1],[2]falsefalsefalsexbrli:monetaryItemTypemonetaryFair value disclosure of collateralized debt obligations as of the reporting date.No definition available.false2Collateralized debt obligations, Fair Value13false 5us-gaap_DerivativeInstrumentsAndHedgesLiabilitiesus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse00[2]falsefalsefalse2truefalsefalse173623000173623[2]falsefalsefalsexbrli:monetaryItemTypemonetarySum as of the balance sheet date of the (a) fair values of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, and (b) the carrying amounts of the liabilities arising from financial instruments or contracts used to mitigate a specified risk (hedge), and which are expected to be extinguished or otherwise disposed of within a year or the normal operating cycle, if longer, net of the effects of master netting arrangements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Derivative instruments, Carrying Value14false 5us-gaap_DerivativeInstrumentsAndHedgesLiabilitiesus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse00[2]falsefalsefalse2truefalsefalse173623000173623[2]falsefalsefalsexbrli:monetaryItemTypemonetarySum as of the balance sheet date of the (a) fair values of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, and (b) the carrying amounts of the liabilities arising from financial instruments or contracts used to mitigate a specified risk (hedge), and which are expected to be extinguished or otherwise disposed of within a year or the normal operating cycle, if longer, net of the effects of master netting arrangements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Derivative instruments, Fair Value15false 5gkk_MortgageNotePayableAtCarryingValuegkk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse4871400048714[1]falsefalsefalse2truefalsefalse00[1]falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying value of mortgage notes payable of loans.No definition available.false2Mortgage note payable, Carrying Value16false 5gkk_MortgageNotePayableAndMezzanineLoansAtFairValuegkk_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse4821800048218[1]USD$falsetruefalse2truefalsefalse00[1]USD$falsetruefalsexbrli:monetaryItemTypemonetaryFair Value of mortgage notes payable and senior and junior mezzanine loans.No definition available.false2Mortgage note payable, Fair Value1Lending investments, mortgages notes payable, and CDOs are classified as Level III due to the significance of unobservable inputs which are based upon management assumptions.2In connection with the disposal of Gramercy Finance, lending investments, CMBS investments, derivative instruments, and collateralized debt obligations were classified as held-for-sale as of December 31, 2012.3Retained CDO Bonds represent the CDOs' subordinate bonds, preferred shares, and ordinary shares, which were retained subsequent to the disposal of Gramercy Finance and were previously eliminated in consolidation.falseFair Value of 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