2.2.0.25falsefalse4034 - Disclosure - Summary of Significant Accounting Policies (Details 5)truefalsefalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010 USD ($) USD ($) / shares $D2010http://www.sec.gov/CIK0001063761duration2010-01-01T00:00:002010-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDPerShareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3true0spg_LoansHeldForInvestmentAbstractspgfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseLoans Held for Investment4false0spg_MortgageLoansOnRealEstateHeldForInvestmentNumberOfLoansspgfalsenadurationThe number of loans on real estate, both mortgage and mezzanine, that are held for investment.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse66falsefalsefalsefalsefalseOtherxbrli:integerItemTypeintegerThe number of loans on real estate, both mortgage and mezzanine, that are held for investment.No authoritative reference available.falsefalseMortgage loans on real estate, number of loans5false0us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgagesus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse395934000395934000falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying amount of the outstanding balance due under the mortgage loan.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule IV -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 29 -Article 12 falsefalseAggregate carrying values of mortgages and mezzanine loans6false0spg_MortgageLoansOnRealEstateWeightedAverageMaturityPeriodspgfalsenadurationRepresents the weighted average period of maturity of mortgage notes and mezzanine loans.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse1313falsefalsefalsefalsefalseOtherxbrli:integerItemTypeintegerRepresents the weighted average period of maturity of mortgage notes and mezzanine loans.No authoritative reference available.falsefalseWeighted average maturity period (in months)7false0spg_MortgageLoansOnRealEstateInterestPrincipalAmortizationPeriodspgfalsenadurationRepresents the period over which interest and principal paid on mortgage notes and mezzanine loans are to be amortized.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse3030falsefalsefalsefalsefalseOtherxbrli:integerItemTypeintegerRepresents the period over which interest and principal paid on mortgage notes and mezzanine loans are to be amortized.No authoritative reference available.falsefalseAmortization period for payments of interest and principal on mortgage notes and mezzanine loans (in years)8false0us-gaap_MortgageLoansOnRealEstateInterestRateus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truetruefalse0.0590.059falsefalsefalsefalsefalseOtherus-types:percentItemTypepureThe stated interest rate on the mortgage loan receivable or the weighted average interest rate on a group of loans.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule IV -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 29 -Article 12 falsefalseWeighted average interest rates on mortgage notes and mezzanine loans (as a percent)9false0us-gaap_MortgageLoansOnRealEstateMinimumInterestRateInRangeus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truetruefalse0.0550.055falsefalsefalsefalsefalseOtherus-types:percentItemTypepureThe lowest stated interest rate within the mortgage loans included in the loan grouping.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule IV -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 29 -Article 12 falsefalseInterest rates on mortgage notes and mezzanine loans, minimum (as a percent)10false0us-gaap_MortgageLoansOnRealEstateMaximumInterestRateInRangeus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truetruefalse0.0700.070falsefalsefalsefalsefalseOtherus-types:percentItemTypepureThe highest stated interest rate within the mortgage loans included in the loan grouping.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule IV -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 29 -Article 12 falsefalseInterest rates on mortgage notes and mezzanine loans, maximum (as a percent)11false0spg_MortgageLoansOnRealEstateInterestIncomespgfalsecreditdurationRepresents the interest income on the mortgage loan receivable.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse46000004600000falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryRepresents the interest income on the mortgage loan receivable.No authoritative reference available.falsefalseInterest income on loans held for investment19Summary of Significant Accounting Policies (Details 5) (USD $)NoRoundingUnKnownUnKnownUnKnowntruetrue