Impax Large Cap Fund Institutional Class Investor Class Equity Securities Risk Market Risk Non-US Securities Risk Focused Portfolio Risk Management Risk Growth Securities Risk Value Securities Risk Medium-Sized Capitalization Company Risk Turnover Risk Emerging Markets Risk Information Technology Sector Risk S&P 500 Index (reflects no deduction for fees, expenses or taxes) Impax Small Cap Fund Institutional Class Investor Class Class A Small- and Medium-Sized Capitalization Company Risk Financial Services Sector Risk S&P 500 Index (reflects no deduction for fees, expenses or taxes) Russell 2000 Index (reflects no deduction for fees, expenses or taxes) Impax US Sustainable Economy Fund Institutional Class Investor Class Class A S&P 500 Index (reflects no deduction for fees, expenses or taxes) Russell 1000 Index (reflects no deduction for fees, expenses or taxes) Impax Global Opportunities Fund Institutional Class Investor Class Currency Risk Healthcare Sector Risk MSCI ACWI (Net) Index (reflects no deduction for fees, expenses or taxes) Impax Global Environmental Markets Fund Institutional Class Investor Class Class A Focused Investment Risk MSCI ACWI (Net) Index (reflects no deduction for fees, expenses or taxes) Impax International Sustainable Economy Fund Institutional Class Investor Class Asian/Pacific Investment Risk European Investment Risk Issuer Risk Medium-Sized Company Risk MSCI EAFE (Net) Index (reflects no deduction for fees, expenses or taxes) Impax Core Bond Fund Institutional Class Investor Class Interest Rate Risk [Member] Liquidity Risk Credit Risk [Member] US Government Securities Risk Mortgage Risk Reinvestment Risk High Yield Securities Risk Bloomberg US Aggregate Bond Index (reflects no deduction for fees, expenses or taxes) Impax High Yield Bond Fund Institutional Class Investor Class Class A Bloomberg US Aggregate Bond Index ICE BofA Merrill Lynch US High Yield-Cash Pay-BB-B (Constrained 2%) Index (reflects no deduction for fees, expenses or taxes) Impax Sustainable Allocation Fund Institutional Class Investor Class Allocation Risk Emerging Markets Securities Risk Underlying Funds and ETFs Risk S&P 500 Index (reflects no deduction for fees, expenses or taxes) Blended Index (reflects no deduction for fees, expenses or taxes) Morningstar Moderate Allocation C000061361Member C000061360Member Index2Member C000043242Member C000043241Member C000128848Member Index4Member C000201507Member C000201508Member C000061358Member C000061357Member C000128849Member Index7Member C000137561Member C000137562Member C000175862Member C000175863Member C000043227Member C000043226Member C000128847Member C000043251Member C000043250Member Index12Member