You can find additional information about the Fund at https://www.amundi.com/usinvestors/Resources/Shareholder-Reports. You can also request this information by contacting us at 1-800-225-6292.

Material Fund Change Notice [Text Block]

This report describes changes to the Fund that occurred during the reporting period.

Additional Information Phone Number

1-800-225-6292

Additional Information Website

https://www.amundi.com/usinvestors/Resources/Shareholder-Reports

Expenses [Text Block]

What were the Fund costs for the last year?

(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	$102	0.92%

Expenses Paid, Amount

$ 102

Expense Ratio, Percent

0.92%

Factors Affecting Performance [Text Block]

How did the Fund perform last year and what affected the Fund performance?

For the fiscal year ended December 31, 2024, the Fund’s Class A shares at NAV returned 22.58%. For the same period, the Fund’s broad-based benchmark the S&P 500 Total Return Index (the “Index”) returned 25.02%.
Sector allocation decisions accounted for the Fund’s benchmark relative underperformance; specifically, an overweight to materials, accounted for the majority of the underperformance. In addition, the Portfolio’s stock selection in health care hurt relative benchmark returns.
Security selection decisions in information technology and consumer staples added the most to relative benchmark returns.

Performance Past Does Not Indicate Future [Text]

The performance data quoted represents past performance, which is no guarantee of future results.

Line Graph [Table Text Block]

Fund Performance

The line graph below shows the change in value of a $10,000 investment made in Class A shares of the Fund at public offering price during the periods shown, compared to that of the S&P 500 Total Return Index.

GROWTH OF $10,000

Average Annual Return [Table Text Block]

AVERAGE ANNUAL TOTAL RETURN	1 Year	5 Years	10 Years
Class A (with sales charge)	15.53%	13.66%	12.46%
Class A (without sales charge)	22.58%	15.01%	13.13%
S&P 500 Total Return Index	25.02%	14.53%	13.10%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Updated Performance Information Location [Text Block]

Call 1-800-225-6292 or visit https://www.amundi.com/usinvestors/Resources/Shareholder-Reports for the most recent month-end performance results.

Net Assets

$ 8,969,098,320

Holdings Count | Holding

^[1]

Advisory Fees Paid, Amount

$ 49,705,321

Investment Company Portfolio Turnover

64.00%

Additional Fund Statistics [Text Block]

KEY FUND STATISTICS
(as of December 31, 2024)

Fund net assets	$8,969,098,320%
Total number of portfolio holdings	44^{^^}
Total advisory fee paid	$49,705,321
Portfolio turnover rate	64%

^{^^}

Excluding short-term investments and all derivative contracts except for options purchased.

Holdings [Text Block]

SECTOR DISTRIBUTION
(as of December 31, 2024 )^*

Information Technology	32.0%
Financials	18.0%
Health Care	11.2%
Industrials	10.5%
Basic Materials	9.3%
Consumer Discretionary	9.0%
Communication Services	5.4%
Consumer Staples	2.5%
Energy	2.1%

^*	As a percentage of total investments excluding short-term investments and all derivative contracts except for options purchased.

Material Fund Change [Text Block]

Material Fund Changes

Amundi Asset Management US, Inc. (the “Adviser”), the Fund’s investment adviser, is currently an indirect, wholly-owned subsidiary of Amundi. On July 9, 2024, Amundi announced that it had entered into a definitive agreement with Victory Capital Holdings, Inc. (“Victory Capital”) to combine the Adviser with Victory Capital, and for Amundi to become a strategic shareholder of Victory Capital (the “Transaction”). Victory Capital is headquartered in San Antonio, Texas. The closing of the Transaction is subject to certain regulatory approvals and other conditions. There is no assurance that the Transaction will close.

Under the terms of the Transaction, subject to Fund shareholder approval, the Fund is expected to be reorganized into a corresponding, newly established Victory Fund advised by Victory Capital Management Inc., an affiliate of Victory Capital (the “Reorganization”). The Fund’s Board of Trustees has approved the Reorganization. The Reorganization is contingent upon the completion of certain conditions, including approval by the shareholders of the Fund. There is no assurance that the shareholders of the Fund will approve the proposal to reorganize the Fund.

For more complete information, you may review the Fund's next prospectus, which we expect to be available by May 1, 2025 at https://www.amundi.com/usinvestors/Products/Mutual-Funds or upon request at 1-800-225-6292.

Summary of Change Legend [Text Block]

Updated Prospectus Phone Number

1-800-225-6292

Updated Prospectus Web Address

https://www.amundi.com/usinvestors/Products/Mutual-Funds

C000011120 [Member]

Shareholder Report [Line Items]

Fund Name

Pioneer Fund

Class Name

Class C

Trading Symbol

PCODX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Pioneer Fund (“Fund”) for the period of January 1, 2024 to December 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at https://www.amundi.com/usinvestors/Resources/Shareholder-Reports. You can also request this information by contacting us at 1-800-225-6292.

Material Fund Change Notice [Text Block]

This report describes changes to the Fund that occurred during the reporting period.

Additional Information Phone Number

1-800-225-6292

Additional Information Website

https://www.amundi.com/usinvestors/Resources/Shareholder-Reports

Expenses [Text Block]

What were the Fund costs for the last year?

(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	$191	1.72%

Expenses Paid, Amount

$ 191

Expense Ratio, Percent

1.72%

Factors Affecting Performance [Text Block]

How did the Fund perform last year and what affected the Fund performance?

For the fiscal year ended December 31, 2024, the Fund’s Class C shares at NAV returned 21.64%. For the same period, the Fund’s broad-based benchmark the S&P 500 Total Return Index (the “Index”) returned 25.02%.
Sector allocation decisions accounted for the Fund’s benchmark relative underperformance; specifically, an overweight to materials, accounted for the majority of the underperformance. In addition, the Portfolio’s stock selection in health care hurt relative benchmark returns.
Security selection decisions in information technology and consumer staples added the most to relative benchmark returns.

Performance Past Does Not Indicate Future [Text]

The performance data quoted represents past performance, which is no guarantee of future results.

Line Graph [Table Text Block]

Fund Performance

The line graph below shows the change in value of a $10,000 investment made in Class C shares of the Fund during the periods shown, compared to that of the S&P 500 Total Return Index.

GROWTH OF $10,000

Average Annual Return [Table Text Block]

AVERAGE ANNUAL TOTAL RETURN	1 Year	5 Years	10 Years
Class C (with contingent deferred sales charge)	20.64%	14.11%	12.24%
Class C (without contingent deferred sales charge)	21.64%	14.11%	12.24%
S&P 500 Total Return Index	25.02%	14.53%	13.10%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Updated Performance Information Location [Text Block]

Call 1-800-225-6292 or visit https://www.amundi.com/usinvestors/Resources/Shareholder-Reports for the most recent month-end performance results.

Net Assets

$ 8,969,098,320

Holdings Count | Holding

^[2]

Advisory Fees Paid, Amount

$ 49,705,321

Investment Company Portfolio Turnover

64.00%

Additional Fund Statistics [Text Block]

KEY FUND STATISTICS
(as of December 31, 2024)

Fund net assets	$8,969,098,320%
Total number of portfolio holdings	44^{^^}
Total advisory fee paid	$49,705,321
Portfolio turnover rate	64%

^{^^}

Excluding short-term investments and all derivative contracts except for options purchased.

Holdings [Text Block]

SECTOR DISTRIBUTION
(as of December 31, 2024 )^*

Information Technology	32.0%
Financials	18.0%
Health Care	11.2%
Industrials	10.5%
Basic Materials	9.3%
Consumer Discretionary	9.0%
Communication Services	5.4%
Consumer Staples	2.5%
Energy	2.1%

^*	As a percentage of total investments excluding short-term investments and all derivative contracts except for options purchased.

Material Fund Change [Text Block]

Material Fund Changes

Summary of Change Legend [Text Block]

Updated Prospectus Phone Number

1-800-225-6292

Updated Prospectus Web Address

https://www.amundi.com/usinvestors/Products/Mutual-Funds

C000202421 [Member]

Shareholder Report [Line Items]

Fund Name

Pioneer Fund

Class Name

Class K

Trading Symbol

PIOKX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Pioneer Fund (“Fund”) for the period of January 1, 2024 to December 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at https://www.amundi.com/usinvestors/Resources/Shareholder-Reports. You can also request this information by contacting us at 1-800-225-6292.

Material Fund Change Notice [Text Block]

This report describes changes to the Fund that occurred during the reporting period.

Additional Information Phone Number

1-800-225-6292

Additional Information Website

https://www.amundi.com/usinvestors/Resources/Shareholder-Reports

Expenses [Text Block]

What were the Fund costs for the last year?

(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 K	$71	0.64%

Expenses Paid, Amount

$ 71

Expense Ratio, Percent

0.64%

Factors Affecting Performance [Text Block]

How did the Fund perform last year and what affected the Fund performance?

For the fiscal year ended December 31, 2024, the Fund’s Class K shares at NAV returned 22.94%. For the same period, the Fund’s broad-based benchmark the S&P 500 Total Return Index (the “Index”) returned 25.02%.
Sector allocation decisions accounted for the Fund’s benchmark relative underperformance; specifically, an overweight to materials, accounted for the majority of the underperformance. In addition, the Portfolio’s stock selection in health care hurt relative benchmark returns.
Security selection decisions in information technology and consumer staples added the most to relative benchmark returns.

Performance Past Does Not Indicate Future [Text]

The performance data quoted represents past performance, which is no guarantee of future results.

Line Graph [Table Text Block]

Fund Performance

The line graph below shows the change in value of a $5 million investment made in Class K shares of the Fund during the periods shown, compared to that of the S&P 500 Total Return Index.

GROWTH OF $5 million

Average Annual Return [Table Text Block]

AVERAGE ANNUAL TOTAL RETURN	1 Year	5 Years	10 Years
Class K	22.94%	15.36%	13.31%
S&P 500 Total Return Index	25.02%	14.53%	13.10%

Performance Inception Date

Dec. 30, 2019

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Updated Performance Information Location [Text Block]

Call 1-800-225-6292 or visit https://www.amundi.com/usinvestors/Resources/Shareholder-Reports for the most recent month-end performance results.

Net Assets

$ 8,969,098,320

Holdings Count | Holding

^[3]

Advisory Fees Paid, Amount

$ 49,705,321

Investment Company Portfolio Turnover

64.00%

Additional Fund Statistics [Text Block]

KEY FUND STATISTICS
(as of December 31, 2024)

Fund net assets	$8,969,098,320%
Total number of portfolio holdings	44^{^^}
Total advisory fee paid	$49,705,321
Portfolio turnover rate	64%

^{^^}

Excluding short-term investments and all derivative contracts except for options purchased.

Holdings [Text Block]

SECTOR DISTRIBUTION
(as of December 31, 2024 )^*

Information Technology	32.0%
Financials	18.0%
Health Care	11.2%
Industrials	10.5%
Basic Materials	9.3%
Consumer Discretionary	9.0%
Communication Services	5.4%
Consumer Staples	2.5%
Energy	2.1%

^*	As a percentage of total investments excluding short-term investments and all derivative contracts except for options purchased.

Material Fund Change [Text Block]

Material Fund Changes

Summary of Change Legend [Text Block]

Updated Prospectus Phone Number

1-800-225-6292

Updated Prospectus Web Address

https://www.amundi.com/usinvestors/Products/Mutual-Funds

C000011122 [Member]

Shareholder Report [Line Items]

Fund Name

Pioneer Fund

Class Name

Class R

Trading Symbol

PIORX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Pioneer Fund (“Fund”) for the period of January 1, 2024 to December 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at https://www.amundi.com/usinvestors/Resources/Shareholder-Reports. You can also request this information by contacting us at 1-800-225-6292.

Material Fund Change Notice [Text Block]

This report describes changes to the Fund that occurred during the reporting period.

Additional Information Phone Number

1-800-225-6292

Additional Information Website

https://www.amundi.com/usinvestors/Resources/Shareholder-Reports

Expenses [Text Block]

What were the Fund costs for the last year?

(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 R	$152	1.37%

Expenses Paid, Amount

$ 152

Expense Ratio, Percent

1.37%

Factors Affecting Performance [Text Block]

How did the Fund perform last year and what affected the Fund performance?

For the fiscal year ended December 31, 2024, the Fund’s Class R shares at NAV returned 22.03%. For the same period, the Fund’s broad-based benchmark the S&P 500 Total Return Index (the “Index”) returned 25.02%.
Sector allocation decisions accounted for the Fund’s benchmark relative underperformance; specifically, an overweight to materials, accounted for the majority of the underperformance. In addition, the Portfolio’s stock selection in health care hurt relative benchmark returns.
Security selection decisions in information technology and consumer staples added the most to relative benchmark returns.

Performance Past Does Not Indicate Future [Text]

The performance data quoted represents past performance, which is no guarantee of future results.

Line Graph [Table Text Block]

Fund Performance

The line graph below shows the change in value of a $10,000 investment made in Class R shares of the Fund during the periods shown, compared to that of the S&P 500 Total Return Index.

GROWTH OF $10,000

Average Annual Return [Table Text Block]

AVERAGE ANNUAL TOTAL RETURN	1 Year	5 Years	10 Years
Class R	22.03%	14.51%	12.66%
S&P 500 Total Return Index	25.02%	14.53%	13.10%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Updated Performance Information Location [Text Block]

Call 1-800-225-6292 or visit https://www.amundi.com/usinvestors/Resources/Shareholder-Reports for the most recent month-end performance results.

Net Assets

$ 8,969,098,320

Holdings Count | Holding

^[4]

Advisory Fees Paid, Amount

$ 49,705,321

Investment Company Portfolio Turnover

64.00%

Additional Fund Statistics [Text Block]

KEY FUND STATISTICS
(as of December 31, 2024)

Fund net assets	$8,969,098,320%
Total number of portfolio holdings	44^{^^}
Total advisory fee paid	$49,705,321
Portfolio turnover rate	64%

^{^^}

Excluding short-term investments and all derivative contracts except for options purchased.

Holdings [Text Block]

SECTOR DISTRIBUTION
(as of December 31, 2024 )^*

Information Technology	32.0%
Financials	18.0%
Health Care	11.2%
Industrials	10.5%
Basic Materials	9.3%
Consumer Discretionary	9.0%
Communication Services	5.4%
Consumer Staples	2.5%
Energy	2.1%

^*	As a percentage of total investments excluding short-term investments and all derivative contracts except for options purchased.

Material Fund Change [Text Block]

Material Fund Changes

Summary of Change Legend [Text Block]

Updated Prospectus Phone Number

1-800-225-6292

Updated Prospectus Web Address

https://www.amundi.com/usinvestors/Products/Mutual-Funds

C000011121 [Member]

Shareholder Report [Line Items]

Fund Name

Pioneer Fund

Class Name

Class Y

Trading Symbol

PYODX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Pioneer Fund (“Fund”) for the period of January 1, 2024 to December 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at https://www.amundi.com/usinvestors/Resources/Shareholder-Reports. You can also request this information by contacting us at 1-800-225-6292.

Material Fund Change Notice [Text Block]

This report describes changes to the Fund that occurred during the reporting period.

Additional Information Phone Number

1-800-225-6292

Additional Information Website

https://www.amundi.com/usinvestors/Resources/Shareholder-Reports

Expenses [Text Block]

What were the Fund costs for the last year?

(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 Y	$71	0.64%

Expenses Paid, Amount

$ 71

Expense Ratio, Percent

0.64%

Factors Affecting Performance [Text Block]

How did the Fund perform last year and what affected the Fund performance?

For the fiscal year ended December 31, 2024, the Fund’s Class Y shares at NAV returned 22.92%. For the same period, the Fund’s broad-based benchmark the S&P 500 Total Return Index (the “Index”) returned 25.02%.
Sector allocation decisions accounted for the Fund’s benchmark relative underperformance; specifically, an overweight to materials, accounted for the majority of the underperformance. In addition, the Portfolio’s stock selection in health care hurt relative benchmark returns.
Security selection decisions in information technology and consumer staples added the most to relative benchmark returns.

Performance Past Does Not Indicate Future [Text]

The performance data quoted represents past performance, which is no guarantee of future results.

Line Graph [Table Text Block]

Fund Performance

The line graph below shows the change in value of a $5 million investment made in Class Y shares of the Fund during the periods shown, compared to that of the S&P 500 Total Return Index.

GROWTH OF $5 million

Average Annual Return [Table Text Block]

AVERAGE ANNUAL TOTAL RETURN	1 Year	5 Years	10 Years
Class Y	22.92%	15.36%	13.44%
S&P 500 Total Return Index	25.02%	14.53%	13.10%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.

Updated Performance Information Location [Text Block]

Call 1-800-225-6292 or visit https://www.amundi.com/usinvestors/Resources/Shareholder-Reports for the most recent month-end performance results.

Net Assets

$ 8,969,098,320

Holdings Count | Holding

^[5]

Advisory Fees Paid, Amount

$ 49,705,321

Investment Company Portfolio Turnover

64.00%

Additional Fund Statistics [Text Block]

KEY FUND STATISTICS
(as of December 31, 2024)

Fund net assets	$8,969,098,320%
Total number of portfolio holdings	44^{^^}
Total advisory fee paid	$49,705,321
Portfolio turnover rate	64%

^{^^}

Excluding short-term investments and all derivative contracts except for options purchased.

Holdings [Text Block]

SECTOR DISTRIBUTION
(as of December 31, 2024 )^*

Information Technology	32.0%
Financials	18.0%
Health Care	11.2%
Industrials	10.5%
Basic Materials	9.3%
Consumer Discretionary	9.0%
Communication Services	5.4%
Consumer Staples	2.5%
Energy	2.1%

^*	As a percentage of total investments excluding short-term investments and all derivative contracts except for options purchased.

Material Fund Change [Text Block]

Material Fund Changes

Summary of Change Legend [Text Block]

Updated Prospectus Phone Number

1-800-225-6292

Updated Prospectus Web Address

https://www.amundi.com/usinvestors/Products/Mutual-Funds

[1]	Excluding short-term investments and all derivative contracts except for options purchased.
[2]	Excluding short-term investments and all derivative contracts except for options purchased.
[3]	Excluding short-term investments and all derivative contracts except for options purchased.
[4]	Excluding short-term investments and all derivative contracts except for options purchased.
[5]	Excluding short-term investments and all derivative contracts except for options purchased.