Parametric Tax-Managed Emerging Markets FundParametric Tax-Managed Emerging Markets FundDparametrictaxmanagedemergingmarketsfundprospectus_17603Parametric Tax-Managed Emerging Markets FundDparametrictaxmanagedemergingmarketsfundsai_17605Parametric Tax-Managed Emerging Markets Fund SAIClass I - C000006391IMarket Risk [Member]Market Risk [Member]Equity Securities Risk [Member]Equity Securities Risk [Member]Tax-Managed Investing Risk [Member]Tax-Managed Investing Risk [Member]Foreign Investment Risk [Member]Foreign Investment Risk [Member]Emerging Markets Investment Risk [Member]Emerging Markets Investment Risk [Member]Frontier Market Investment Risk [Member]Frontier Market Investment Risk [Member]China Region Risk [Member]China Region Risk [Member]Currency Risk [Member]Currency Risk [Member]Focused Investment Risk [Member]Focused Investment Risk [Member]Geographic Risk [Member]Geographic Risk [Member]Smaller Company Risk [Member]Smaller Company Risk [Member]Liquidity Risk [Member]Liquidity Risk [Member]Real Estate Risk [Member]Real Estate Risk [Member]Rules-Based Management Risks [Member]Rules-Based Management Risks [Member]Securities Lending Risk [Member]Securities Lending Risk [Member]General Fund Investing Risks [Member]General Fund Investing Risks [Member]Return After Taxes on DistributionsReturn After Taxes on DistributionsReturn After Taxes on Distributions and Sale of Fund SharesReturn After Taxes on Distributions and Sale of Fund SharesMSCI Emerging Markets Index (reflects net dividends, which reflect the deduction of withholding taxes)MSCI Emerging Markets Index (reflects net dividends, which reflect the deduction of withholding taxes)