XFUNDS Memory Income ETF Memory Companies Risk [Member] Semiconductor Companies Risks [Member] Technology Sector Risk [Member] Equity Market Risk [Member] Derivatives Risk [Member] Options Contracts [Member] Swap Agreements [Member] Counterparty Risk [Member] Concentration Risk [Member] Foreign Investment Risk [Member] Foreign Securities Risk [Member] Emerging Markets Risk [Member] Depositary Receipt Risk [Member] Geographic Focus Risk [Member] Japan Risk [Member] South Korea Risk [Member] Taiwan Risk [Member] Market Capitalization Risk [Member] Large-Capitalization Investing [Member] Mid-Capitalization Investing [Member] Small-Capitalization Investing [Member] Micro-Capitalization Investing [Member] Distribution Risk [Member] NAV Erosion Risk Due to Distributions [Member] Economic and Market Risk [Member] ETF Risks [Member] Authorized Participants, Market Makers, and Liquidity Providers Concentration Risk [Member] Cash Redemption Risk [Member] Costs of Buying or Selling Shares [Member] Shares May Trade at Prices Other Than NAV [Member] Trading [Member] High Portfolio Turnover Risk [Member] Inflation Risk [Member] Management Risk [Member] New Fund Risk [Member] Operational Risk [Member] U.S. Government and U.S. Agency Obligations Risk [Member] XFUNDS Memory Income ETF [Member] XFUNDS Memory Income ETF XFUNDS Memory Income ETF U.S. Government and U.S. Agency Obligations Risk. Operational Risk. New Fund Risk. Management Risk. Inflation Risk. High Portfolio Turnover Risk. Trading. Shares May Trade at Prices Other Than NAV. Costs of Buying or Selling Shares. Cash Redemption Risk. Authorized Participants, Market Makers, and Liquidity Providers Concentration Risk. ETF Risks. Economic and Market Risk. NAV Erosion Risk Due to Distributions. Distribution Risk. Micro-Capitalization Investing. Small-Capitalization Investing. Mid-Capitalization Investing. Large-Capitalization Investing. Market Capitalization Risk. Japan Risk. South Korea Risk. Taiwan Risk. Geographic Focus Risk. Depositary Receipt Risk. Emerging Markets Risk. Foreign Securities Risk. Foreign Investment Risk. Concentration Risk. Counterparty Risk. Swap Agreements. Options Contracts. Derivatives Risk. Equity Market Risk. Technology Sector Risk. Semiconductor Companies Risks. Memory Companies Risk.