Discovery Portfolio Discovery Portfolio Corporate Bond Portfolio Corporate Bond Portfolio Ultra-Short Income Portfolio Ultra-Short Income Portfolio Global Strategist Portfolio Global Strategist Portfolio Dmsiftdiscoveryprojanuaryb_17088 MSIFT Discovery Portfolio - Classes I, A, L, C and R6 Dmsiftcorporatebondportfolioprojanuaryb_17092 MSIFT Corporate Bond Portfolio - Classes I, A, L, and C Dmsiftultrashortincomeportfolioprojanuaryb_17095 MSIFT Ultra-Short Portfolios - Classes IR, Institutional Class, Class A Dmsiftglobalstrategistprojanuaryb_17086 MSIFT Global Strategist Portfolio - Classes I, A, L, C and R6 Dmsiftsaijanuaryb_17020 MSIFT_SAI_January 2026_485B Class I - C000011563 Class I Class A - C000011562 Class A Class L - C000113795 Class L Class C - C000155934 Class C Class R6 - C000129401 Class R6 Class I - C000011549 Class I Class A - C000011548 Class A Class L - C000065127 Class L Class C - C000155931 Class C Class IR - C000163599 Class IR Class Institutional - C000163598 Institutional Class Class A - C000163600 Class A Class I - C000011556 Class I Class A - C000011555 Class A Class L - C000113792 Class L Class C - C000155933 Class C Class R6 - C000156275 Class R6 Equity Securities Equity Securities [Member] Mid Cap Companies Mid Cap Companies [Member] Foreign and Emerging Market Securities Foreign and Emerging Market Securities [Member] Foreign Currency Forward Exchange Contracts Foreign Currency Forward Exchange Contracts [Member] Foreign Currency Foreign Currency [Member] Liquidity Liquidity [Member] Focused Investing Focused Investing [Member] Private Placements and Restricted Securities Private Placements and Restricted Securities [Member] Information Technology Sector Risk Information Technology Sector Risk [Member] Market and Geopolitical Risk Market and Geopolitical Risk [Member] Active Management Risk Active Management Risk [Member] Russell 3000® Index (reflects no deduction for fees, expenses or taxes) Russell 3000® Index (reflects no deduction for fees, expenses or taxes) Russell Midcap® Growth Index (reflects no deduction for fees, expenses or taxes) Russell Midcap® Growth Index (reflects no deduction for fees, expenses or taxes) Credit and Interest Rate Risk Credit and Interest Rate Risk [Member] Fixed-Income Securities Fixed-Income Securities [Member] Corporate Debt Obligations Corporate Debt Obligations [Member] High Yield Securities (Junk Bonds) High Yield Securities (Junk Bonds) [Member] Derivatives Derivatives [Member] Financial Services Industry Risk Financial Services Industry Risk [Member] Industrials Sector Risk Industrials Sector Risk [Member] When-Issued Securities, Delayed Delivery Securities, TBAs and Forward Commitments When-Issued Securities, Delayed Delivery Securities, TBAs and Forward Commitments [Member] Portfolio Turnover Portfolio Turnover [Member] ESG Investment Risk ESG Investment Risk [Member] Bloomberg U.S. Universal Index (reflects no deduction for fees, expenses or taxes) Bloomberg U.S. Universal Index (reflects no deduction for fees, expenses or taxes) Bloomberg U.S. Corporate Index (reflects no deduction for fees, expenses or taxes) Bloomberg U.S. Corporate Index (reflects no deduction for fees, expenses or taxes) U.S. Government Securities U.S. Government Securities [Member] Asset-Backed Securities Asset-Backed Securities [Member] Repurchase Agreements Repurchase Agreements [Member] Money Market Instrument Risk Money Market Instrument Risk [Member] Foreign Money Market Securities Foreign Money Market Securities [Member] Foreign Securities Foreign Securities [Member] Municipals Municipals [Member] Commercial Paper Commercial Paper [Member] Non-Money Market Fund Non-Money Market Fund [Member] Large Transactions Risk Large Transactions Risk [Member] Bloomberg U.S. Universal Index (reflects no deductions for fees, expenses or taxes) Bloomberg U.S. Universal Index (reflects no deductions for fees, expenses or taxes) ICE BofA 3-Month U.S. Treasury Bill Index (reflects no deductions for fees, expenses or taxes) ICE BofA 3-Month U.S. Treasury Bill Index (reflects no deductions for fees, expenses or taxes) Convertible Securities Convertible Securities [Member] Mortgage-Backed Securities Mortgage-Backed Securities [Member] REITs REITs [Member] Sovereign Debt Securities Sovereign Debt Securities [Member] Commodity-Related Investments Risk Commodity-Related Investments Risk [Member] Inflation-Linked Securities Risk Inflation-Linked Securities Risk [Member] Investment Company Securities Investment Company Securities [Member] Subsidiary Risk Subsidiary Risk [Member] Tax Risk Tax Risk [Member] China Risk China Risk [Member] MSCI All Country World Index (reflects no deduction for fees, expenses or taxes) MSCI All Country World Index (reflects no deduction for fees, expenses or taxes) Customized MSIM Global Allocation Index (reflects no deduction for fees, expenses or taxes) Customized MSIM Global Allocation Index (reflects no deduction for fees, expenses or taxes)