Defiance 2X Daily Target Short Pure Space Index ETF Index Positive Performance Risk [Member] Compounding and Market Volatility Risk [Member] Daily Correlation/Tracking Risk [Member] Short Sale Exposure Risk [Member] Aggressive Investment Technique Risk [Member] Concentration Risk [Member] Space Company Investing Risk [Member] Derivatives Risk [Member] Swap Agreements [Member] Options Contracts [Member] Counterparty Risk [Member] Intra-Day Investment Risk [Member] Foreign Securities Risk [Member] ADR Risk [Member] Fixed Income Securities Risk [Member] Rebalancing Risk [Member] Leverage 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] Liquidity Risks [Member] Economic and Market Risk [Member] High Portfolio Turnover Risk [Member] Tracking Error Risk [Member] Liquidity Risk [Member] Market Capitalization Risk [Member] Large-Capitalization Investing [Member] Small- and Mid-Capitalization Company Risk [Member] Emerging Markets Securities Risk [Member] Money Market Instrument Risk [Member] New Fund Risk [Member] Operational Risk [Member] U.S. Government and U.S. Agency Obligations Risk [Member] Tax Risk [Member] Defiance 2X Daily Target Short Taiwan ETF Reference Asset Price Appreciation Risk [Member] Indirect Investment in Reference Asset Risk [Member] Reference Asset Good Performance Risk [Member] Single Issuer Risk [Member] Geopolitical Risk [Member] Trading Halt Risk [Member] Defiance 2X Daily Target Short Pure Space Index ETF [Member] Defiance 2X Daily Target Short Taiwan ETF [Member] Defiance 2X Daily Target Short Pure Space Index ETF. Defiance 2X Daily Target Short Pure Space Index ETF. Defiance 2X Daily Target Short Taiwan ETF. Defiance 2X Daily Target Short Taiwan ETF. Tax Risk. U.S. Government and U.S. Agency Obligations Risk. Operational Risk. Trading Halt Risk. New Fund Risk. Money Market Instrument Risk. Liquidity Risk. Tracking Error Risk. High Portfolio Turnover Risk. Liquidity Risks. 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. Geopolitical Risk. Economic and Market Risk. Rebalancing Risk. Fixed Income Securities Risk. Intra-Day Investment Risk. Counterparty Risk. Options Contracts. Swap Agreements. Derivatives Risk. Leverage Risk. Aggressive Investment Technique Risk. Concentration Risk. Short Sale Exposure Risk. Daily Correlation/Tracking Risk. Compounding and Market Volatility Risk. Single Issuer Risk. Reference Asset Good Performance Risk. Indirect Investment in Reference Asset Risk. Reference Asset Price Appreciation Risk. Space Company Investing Risk. Small- and Mid-Capitalization Company Risk. Index Positive Performance Risk. Foreign Securities Risk. Emerging Markets Securities Risk. Market Capitalization Risk. ADR Risk. Large-Capitalization Investing.