v3.26.1
Shareholder Report
 6 Months Ended
May 31, 2026
USD ($)
$ / shares
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name MainGate Trust
Entity Central Index Key 0001505064
Entity Investment Company Type N-1A
Document Period End Date May 31, 2026
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Class A  
Shareholder Report [Line Items]  
Fund Name MainGate MLP Fund
Class Name Class A
Trading Symbol AMLPX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the MainGate MLP Fund (the “Fund”) for the period of  December 1, 2025 to May 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://maingatefunds.com/literature/. You can also request this information by contacting us at  1-855-MLP-FUND (1-855-657-3863).
Material Fund Change Notice [Text Block]
This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-855-MLP-FUND (1-855-657-3863)
Additional Information Website https://maingatefunds.com/literature/
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?  (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*
Class A
$92
1.70%
[1]
Expenses Paid, Amount $ 92
Expense Ratio, Percent 1.70%
Net Assets $ 834,604,338
Holdings Count | $ / shares 16
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of May 31, 2026)
Net Assets
$834,604,338
Number of Holdings
16
Portfolio Turnover
4%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (% of total investments as of  May 31, 2026)
Top 10 Issuers
(%)
Targa Resources Corp.
16.9%
Energy Transfer, L.P.
12.0%
MPLX, L.P.
11.5%
Plains GP Holdings, L.P.
10.9%
Western Midstream Partners, L.P.
9.5%
Williams Companies, Inc.
8.3%
ONEOK, Inc.
7.8%
Cheniere Energy, Inc.
7.1%
Enterprise Products Partners, L.P.
7.0%
Phillips 66
2.1%
Industry Breakdown (%)
image
Updated Prospectus Web Address https://maingatefunds.com/literature/
Class C  
Shareholder Report [Line Items]  
Fund Name MainGate MLP Fund
Class Name Class C
Trading Symbol MLCPX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the MainGate MLP Fund (the “Fund”) for the period of  December 1, 2025 to May 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://maingatefunds.com/literature/. You can also request this information by contacting us at  1-855-MLP-FUND (1-855-657-3863).
Material Fund Change Notice [Text Block]
This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-855-MLP-FUND (1-855-657-3863)
Additional Information Website https://maingatefunds.com/literature/
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?  (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*
Class C
$133
2.45%
[2]
Expenses Paid, Amount $ 133
Expense Ratio, Percent 2.45%
Net Assets $ 834,604,338
Holdings Count | $ / shares 16
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of May 31, 2026)
Net Assets
$834,604,338
Number of Holdings
16
Portfolio Turnover
4%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (% of total investments as of  May 31, 2026)
Top 10 Issuers
(%)
Targa Resources Corp.
16.9%
Energy Transfer, L.P.
12.0%
MPLX, L.P.
11.5%
Plains GP Holdings, L.P.
10.9%
Western Midstream Partners, L.P.
9.5%
Williams Companies, Inc.
8.3%
ONEOK, Inc.
7.8%
Cheniere Energy, Inc.
7.1%
Enterprise Products Partners, L.P.
7.0%
Phillips 66
2.1%
Industry Breakdown (%)
image
Updated Prospectus Web Address https://maingatefunds.com/literature/
Class I  
Shareholder Report [Line Items]  
Fund Name MainGate MLP Fund
Class Name Class I
Trading Symbol IMLPX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the MainGate MLP Fund (the “Fund”) for the period of  December 1, 2025 to May 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at https://maingatefunds.com/literature/. You can also request this information by contacting us at  1-855-MLP-FUND (1-855-657-3863).
Material Fund Change Notice [Text Block]
This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-855-MLP-FUND (1-855-657-3863)
Additional Information Website https://maingatefunds.com/literature/
Expenses [Text Block]
WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS?  (based on a hypothetical $10,000 investment)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*
Class I
$79
1.45%
[3]
Expenses Paid, Amount $ 79
Expense Ratio, Percent 1.45%
Net Assets $ 834,604,338
Holdings Count | $ / shares 16
Investment Company Portfolio Turnover 4.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of May 31, 2026)
Net Assets
$834,604,338
Number of Holdings
16
Portfolio Turnover
4%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (% of total investments as of  May 31, 2026)
Top 10 Issuers
(%)
Targa Resources Corp.
16.9%
Energy Transfer, L.P.
12.0%
MPLX, L.P.
11.5%
Plains GP Holdings, L.P.
10.9%
Western Midstream Partners, L.P.
9.5%
Williams Companies, Inc.
8.3%
ONEOK, Inc.
7.8%
Cheniere Energy, Inc.
7.1%
Enterprise Products Partners, L.P.
7.0%
Phillips 66
2.1%
Industry Breakdown (%)
image
Updated Prospectus Web Address https://maingatefunds.com/literature/
[1]
* Annualized
[2]
* Annualized
[3]
* Annualized