v3.26.1
Shareholder Report
 6 Months Ended
Jun. 30, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name EATON VANCE MUTUAL FUNDS TRUST
Entity Central Index Key 0000745463
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2026
Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
C000101132  
Shareholder Report [Line Items]  
Fund Name Parametric Commodity Strategy Fund
Class Name Class I
Trading Symbol EIPCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Parametric Commodity Strategy Fund for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/parametric-fund-documents.php. You can also request this information by contacting us at 1-800-260-0761.
Additional Information Phone Number 1-800-260-0761
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/parametric-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$35
0.67%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Expenses Paid, Amount $ 35
Expense Ratio, Percent 0.67% [1]
AssetsNet $ 2,920,203,178
Holdings Count | Holding 94
InvestmentCompanyPortfolioTurnover 0.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$2,920,203,178
# of Portfolio Holdings (including derivatives)
94
Portfolio Turnover Rate
0%
Holdings [Text Block]

Asset Allocation (% of total investments)

Group By Asset Type Chart
Table Summary
Value
Value
Exchange-Traded Funds
3.8%
Short-Term Investments - other
4.3%
Short-Term Investments - U.S. Treasury Obligations
91.9%
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-260-0761
C000111445  
Shareholder Report [Line Items]  
Fund Name Parametric Commodity Strategy Fund
Class Name Class A
Trading Symbol EAPCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Parametric Commodity Strategy Fund for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/parametric-fund-documents.php. You can also request this information by contacting us at 1-800-260-0761.
Additional Information Phone Number 1-800-260-0761
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/parametric-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$49
0.92%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Expenses Paid, Amount $ 49
Expense Ratio, Percent 0.92% [2]
AssetsNet $ 2,920,203,178
Holdings Count | Holding 94
InvestmentCompanyPortfolioTurnover 0.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$2,920,203,178
# of Portfolio Holdings (including derivatives)
94
Portfolio Turnover Rate
0%
Holdings [Text Block]

Asset Allocation (% of total investments)

Group By Asset Type Chart
Table Summary
Value
Value
Exchange-Traded Funds
3.8%
Short-Term Investments - other
4.3%
Short-Term Investments - U.S. Treasury Obligations
91.9%
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-260-0761
C000014418  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Stock Fund
Class Name Class A
Trading Symbol EAERX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Stock Fund for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$50
0.98%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and Stock Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 50
Expense Ratio, Percent 0.98% [3]
AssetsNet $ 102,106,708
Holdings Count | Holding 58
InvestmentCompanyPortfolioTurnover 28.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$102,106,708
# of Portfolio Holdings (for Stock Portfolio)
58
Portfolio Turnover Rate (for Stock Portfolio)
28%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.0%Footnote Reference*
Real Estate
1.5%
Materials
1.6%
Utilities
1.8%
Energy
3.4%
Consumer Staples
3.9%
Financials
9.2%
Consumer Discretionary
9.3%
Industrials
9.4%
Health Care
9.5%
Communication Services
12.3%
Information Technology
38.1%
Footnote Description
Footnote*
 Amount is less than 0.05%.
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
8.5%
Alphabet, Inc., Class C
6.6%
Apple, Inc.
5.8%
Microsoft Corp.
4.9%
Amazon.com, Inc.
4.7%
Broadcom, Inc.
4.0%
JPMorgan Chase & Co.
3.2%
Eli Lilly & Co.
2.8%
Visa, Inc., Class A
2.7%
Coca-Cola Co.
2.7%
Total
45.9%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
C000081632  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Stock Fund
Class Name Class C
Trading Symbol ECERX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Stock Fund for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$88
1.73%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and Stock Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 88
Expense Ratio, Percent 1.73% [4]
AssetsNet $ 102,106,708
Holdings Count | Holding 58
InvestmentCompanyPortfolioTurnover 28.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$102,106,708
# of Portfolio Holdings (for Stock Portfolio)
58
Portfolio Turnover Rate (for Stock Portfolio)
28%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.0%Footnote Reference*
Real Estate
1.5%
Materials
1.6%
Utilities
1.8%
Energy
3.4%
Consumer Staples
3.9%
Financials
9.2%
Consumer Discretionary
9.3%
Industrials
9.4%
Health Care
9.5%
Communication Services
12.3%
Information Technology
38.1%
Footnote Description
Footnote*
 Amount is less than 0.05%.
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
8.5%
Alphabet, Inc., Class C
6.6%
Apple, Inc.
5.8%
Microsoft Corp.
4.9%
Amazon.com, Inc.
4.7%
Broadcom, Inc.
4.0%
JPMorgan Chase & Co.
3.2%
Eli Lilly & Co.
2.8%
Visa, Inc., Class A
2.7%
Coca-Cola Co.
2.7%
Total
45.9%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
C000047558  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Stock Fund
Class Name Class I
Trading Symbol EIERX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Stock Fund for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$37
0.73%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and Stock Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 37
Expense Ratio, Percent 0.73% [5]
AssetsNet $ 102,106,708
Holdings Count | Holding 58
InvestmentCompanyPortfolioTurnover 28.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$102,106,708
# of Portfolio Holdings (for Stock Portfolio)
58
Portfolio Turnover Rate (for Stock Portfolio)
28%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.0%Footnote Reference*
Real Estate
1.5%
Materials
1.6%
Utilities
1.8%
Energy
3.4%
Consumer Staples
3.9%
Financials
9.2%
Consumer Discretionary
9.3%
Industrials
9.4%
Health Care
9.5%
Communication Services
12.3%
Information Technology
38.1%
Footnote Description
Footnote*
 Amount is less than 0.05%.
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
8.5%
Alphabet, Inc., Class C
6.6%
Apple, Inc.
5.8%
Microsoft Corp.
4.9%
Amazon.com, Inc.
4.7%
Broadcom, Inc.
4.0%
JPMorgan Chase & Co.
3.2%
Eli Lilly & Co.
2.8%
Visa, Inc., Class A
2.7%
Coca-Cola Co.
2.7%
Total
45.9%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
C000014485  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Tax-Managed Growth Fund 1.1
Class Name Class A
Trading Symbol ETTGX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Tax-Managed Growth Fund 1.1 for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$37
0.71%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and the Tax-Managed Growth Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 37
Expense Ratio, Percent 0.71% [6]
AssetsNet $ 3,143,805,408
Holdings Count | Holding 107
InvestmentCompanyPortfolioTurnover 11.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$3,143,805,408
# of Portfolio Holdings (for Tax-Managed Growth Portfolio)
107
Portfolio Turnover Rate (for Tax-Managed Growth Portfolio)
11%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.4%
Utilities
0.7%
Materials
1.2%
Energy
2.2%
Consumer Staples
3.8%
Health Care
8.2%
Industrials
9.8%
Consumer Discretionary
10.6%
Communication Services
12.8%
Financials
13.6%
Information Technology
36.7%
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
9.1%
Amazon.com, Inc.
5.4%
Apple, Inc.
4.9%
Alphabet, Inc., Class A
4.1%
Alphabet, Inc., Class C
4.1%
Microsoft Corp.
3.5%
Meta Platforms, Inc., Class A
3.4%
Broadcom, Inc.
3.3%
Advanced Micro Devices, Inc.
2.7%
Berkshire Hathaway, Inc., Class B
2.5%
Total
43.0%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
C000014487  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Tax-Managed Growth Fund 1.1
Class Name Class C
Trading Symbol ECTGX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Tax-Managed Growth Fund 1.1 for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$75
1.46%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and the Tax-Managed Growth Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 75
Expense Ratio, Percent 1.46% [7]
AssetsNet $ 3,143,805,408
Holdings Count | Holding 107
InvestmentCompanyPortfolioTurnover 11.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$3,143,805,408
# of Portfolio Holdings (for Tax-Managed Growth Portfolio)
107
Portfolio Turnover Rate (for Tax-Managed Growth Portfolio)
11%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.4%
Utilities
0.7%
Materials
1.2%
Energy
2.2%
Consumer Staples
3.8%
Health Care
8.2%
Industrials
9.8%
Consumer Discretionary
10.6%
Communication Services
12.8%
Financials
13.6%
Information Technology
36.7%
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
9.1%
Amazon.com, Inc.
5.4%
Apple, Inc.
4.9%
Alphabet, Inc., Class A
4.1%
Alphabet, Inc., Class C
4.1%
Microsoft Corp.
3.5%
Meta Platforms, Inc., Class A
3.4%
Broadcom, Inc.
3.3%
Advanced Micro Devices, Inc.
2.7%
Berkshire Hathaway, Inc., Class B
2.5%
Total
43.0%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
C000014488  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Tax-Managed Growth Fund 1.1
Class Name Class I
Trading Symbol EITMX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Tax-Managed Growth Fund 1.1 for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$24
0.46%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and the Tax-Managed Growth Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 24
Expense Ratio, Percent 0.46% [8]
AssetsNet $ 3,143,805,408
Holdings Count | Holding 107
InvestmentCompanyPortfolioTurnover 11.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$3,143,805,408
# of Portfolio Holdings (for Tax-Managed Growth Portfolio)
107
Portfolio Turnover Rate (for Tax-Managed Growth Portfolio)
11%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.4%
Utilities
0.7%
Materials
1.2%
Energy
2.2%
Consumer Staples
3.8%
Health Care
8.2%
Industrials
9.8%
Consumer Discretionary
10.6%
Communication Services
12.8%
Financials
13.6%
Information Technology
36.7%
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
9.1%
Amazon.com, Inc.
5.4%
Apple, Inc.
4.9%
Alphabet, Inc., Class A
4.1%
Alphabet, Inc., Class C
4.1%
Microsoft Corp.
3.5%
Meta Platforms, Inc., Class A
3.4%
Broadcom, Inc.
3.3%
Advanced Micro Devices, Inc.
2.7%
Berkshire Hathaway, Inc., Class B
2.5%
Total
43.0%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
C000014466  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Tax-Managed Growth Fund 1.2
Class Name Class A
Trading Symbol EXTGX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Tax-Managed Growth Fund 1.2 for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$44
0.86%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and the Tax-Managed Growth Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 44
Expense Ratio, Percent 0.86% [9]
AssetsNet $ 1,843,225,320
Holdings Count | Holding 107
InvestmentCompanyPortfolioTurnover 11.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$1,843,225,320
# of Portfolio Holdings (for Tax-Managed Growth Portfolio)
107
Portfolio Turnover Rate (for Tax-Managed Growth Portfolio)
11%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.4%
Utilities
0.7%
Materials
1.2%
Energy
2.2%
Consumer Staples
3.8%
Health Care
8.2%
Industrials
9.8%
Consumer Discretionary
10.6%
Communication Services
12.8%
Financials
13.6%
Information Technology
36.7%
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
9.1%
Amazon.com, Inc.
5.4%
Apple, Inc.
4.9%
Alphabet, Inc., Class A
4.1%
Alphabet, Inc., Class C
4.1%
Microsoft Corp.
3.5%
Meta Platforms, Inc., Class A
3.4%
Broadcom, Inc.
3.3%
Advanced Micro Devices, Inc.
2.7%
Berkshire Hathaway, Inc., Class B
2.5%
Total
43.0%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
C000014468  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Tax-Managed Growth Fund 1.2
Class Name Class C
Trading Symbol EZTGX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Tax-Managed Growth Fund 1.2 for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$83
1.61%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and the Tax-Managed Growth Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 83
Expense Ratio, Percent 1.61% [10]
AssetsNet $ 1,843,225,320
Holdings Count | Holding 107
InvestmentCompanyPortfolioTurnover 11.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$1,843,225,320
# of Portfolio Holdings (for Tax-Managed Growth Portfolio)
107
Portfolio Turnover Rate (for Tax-Managed Growth Portfolio)
11%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.4%
Utilities
0.7%
Materials
1.2%
Energy
2.2%
Consumer Staples
3.8%
Health Care
8.2%
Industrials
9.8%
Consumer Discretionary
10.6%
Communication Services
12.8%
Financials
13.6%
Information Technology
36.7%
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
9.1%
Amazon.com, Inc.
5.4%
Apple, Inc.
4.9%
Alphabet, Inc., Class A
4.1%
Alphabet, Inc., Class C
4.1%
Microsoft Corp.
3.5%
Meta Platforms, Inc., Class A
3.4%
Broadcom, Inc.
3.3%
Advanced Micro Devices, Inc.
2.7%
Berkshire Hathaway, Inc., Class B
2.5%
Total
43.0%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
C000014469  
Shareholder Report [Line Items]  
Fund Name Eaton Vance Tax-Managed Growth Fund 1.2
Class Name Class I
Trading Symbol EITGX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Eaton Vance Tax-Managed Growth Fund 1.2 for the period of January 1, 2026 to June 30, 2026.
Additional Information [Text Block] You can find additional information about the Fund at www.eatonvance.com/open-end-mutual-fund-documents.php. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?Footnote Reference*

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$31
0.61%Footnote Reference1
Footnote Description
Footnote1
 Annualized
Footnote*
 Expenses in the table reflect the expenses of both the Fund and the Tax-Managed Growth Portfolio, the Portfolio in which it invests.
Expenses Paid, Amount $ 31
Expense Ratio, Percent 0.61% [11]
AssetsNet $ 1,843,225,320
Holdings Count | Holding 107
InvestmentCompanyPortfolioTurnover 11.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Table Summary
Total Net Assets
$1,843,225,320
# of Portfolio Holdings (for Tax-Managed Growth Portfolio)
107
Portfolio Turnover Rate (for Tax-Managed Growth Portfolio)
11%
Holdings [Text Block]

Sector Allocation (% of total investments)

Group By Country Chart
Table Summary
Value
Value
Short-Term Investments
0.4%
Utilities
0.7%
Materials
1.2%
Energy
2.2%
Consumer Staples
3.8%
Health Care
8.2%
Industrials
9.8%
Consumer Discretionary
10.6%
Communication Services
12.8%
Financials
13.6%
Information Technology
36.7%
Largest Holdings [Text Block]

Top Ten Holdings (% of total investments)Footnote Referencea

Table Summary
NVIDIA Corp.
9.1%
Amazon.com, Inc.
5.4%
Apple, Inc.
4.9%
Alphabet, Inc., Class A
4.1%
Alphabet, Inc., Class C
4.1%
Microsoft Corp.
3.5%
Meta Platforms, Inc., Class A
3.4%
Broadcom, Inc.
3.3%
Advanced Micro Devices, Inc.
2.7%
Berkshire Hathaway, Inc., Class B
2.5%
Total
43.0%
Footnote Description
Footnotea
 Excluding cash equivalents
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
[1] Annualized
[2] Annualized
[3] Annualized
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[5] Annualized
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