v3.25.4
Average Annual Total Returns
 12 Months Ended 60 Months Ended 120 Months Ended 168 Months Ended
Sep. 30, 2025
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
 [1]
Class A          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   (2.54%) 21.83% 5.61% 4.40%
Performance Inception Date Dec. 31, 2010        
Class C          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent   0.58% 22.06% 5.31% 3.93%
Performance Inception Date Dec. 31, 2010        
Class I Shares          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return Before Taxes        
Average Annual Return, Percent [2],[3]   2.52% 23.35% 6.37% 4.98%
Performance Inception Date [2],[3] Dec. 31, 2010        
Class I Shares | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions        
Average Annual Return, Percent [2],[3]   1.23% 21.55% 5.45% 4.33%
Class I Shares | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent [2],[3]   2.42% 18.77% 4.84% 3.85%
Alerian MLP Index          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Alerian MLP Index        
Average Annual Return, Percent [4]   9.76% 25.96% 8.85% 6.33%
Alerian Midstream Energy Select Index          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Alerian Midstream Energy Select Index        
Average Annual Return, Percent [5]   6.58% 24.26% 12.70%
Alerian Midstream Energy Index          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] Alerian Midstream Energy Index        
Average Annual Return, Percent [6]   4.98% 23.82%
S&P 500 Index          
Prospectus [Line Items]          
Average Annual Return, Label [Optional Text] S&P 500 Index        
Average Annual Return, Percent [7]   17.88% 14.42% 14.82% 14.06%
[1] The Predecessor Fund commenced operations on December 31, 2010.
[2] Returns for Class I Shares prior to February 5, 2018 reflect the performance of the Predecessor Fund’s Institutional Class Shares.
[3] The Predecessor Fund offered Institutional Class Shares. Holders of Institutional Class Shares received Class Y Shares of the Fund in exchange for those Shares.
[4] The Alerian MLP Index, the leading gauge of energy infrastructure Master Limited Partnerships (MLPs), is a capped, float-adjusted, capitalization-weighted index, whose constituents earn the majority of their cash flow from midstream activities involving energy commodities.
[5] The Alerian Midstream Energy Select Index is a capped, float-adjusted, capitalization-weighted index composite of North American energy infrastructure companies, whose constituents are engaged in midstream activities involving energy commodities. Data for the Alerian Midstream Energy Select Index is unavailable prior to its inception date of April 1, 2013.
[6] The Alerian Midstream Energy Index is a capped, float-adjusted, capitalization-weighted index composite of North American energy infrastructure companies, whose constituents earn the majority of their cash flow from midstream activities involving energy commodities. Data for the Alerian Midstream Energy Index is unavailable prior to its inception date of June 25, 2018.
[7] The S&P 500® Index is an unmanaged weighted index of 500 large company stocks that is widely recognized as representative of the performance of the U.S. stock market.