Performance Management - DELAWARE GROUP EQUITY FUNDS IV - A, C, R, and Institutional |
Mar. 31, 2026 |
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| Nomura Asset Strategy Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Asset Strategy Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance. The
Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in
the future. The returns reflect
any expense caps in effect during these periods. The returns would be lower without the expense caps.
On April 30, 2021, Delaware Management Company
became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy. Performance prior to November 15, 2021 reflects the Fund’s former strategy;
its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
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| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
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| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 6.51%.
During the periods illustrated in this bar chart, Class A’s highest
quarterly return was 17.88%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -19.74%
for the quarter ended March 31,
2020. The maximum Class A
sales charge of 5.75%, which is normally
deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
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| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
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| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees or expenses | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
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| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Asset Strategy Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 6.51%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 6.51% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 17.88% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (19.74%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Balanced Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Balanced Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance. The
Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in
the future. The returns reflect
any expense caps in effect during these periods. The returns would be lower without the expense caps.
On April 30, 2021, Delaware Management Company
became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy. Performance prior to November 15, 2021 reflects the Fund’s former strategy;
its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
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| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
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| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 7.19%.
During the periods illustrated in this bar chart, Class A’s highest
quarterly return was 15.62%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -16.28%
for the quarter ended March 31,
2020. The maximum Class A
sales charge of 5.75%, which is normally
deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
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| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
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| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses, or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
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| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Balanced Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 7.19%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 7.19% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 15.62% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (16.28%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Core Equity Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Core Equity Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance. The
Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in
the future. The returns reflect
any expense caps in effect during these periods. The returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
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| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 10.75%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 20.29%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -17.74%
for the quarter ended March 31,
2020. The maximum Class A
sales charge of 5.75%, which is normally
deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
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| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
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| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses, or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
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| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Core Equity Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 10.75%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 10.75% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 20.29% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (17.74%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Global Growth Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Global Growth Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance. The
Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in
the future. The returns reflect
any expense caps in effect during these periods. The returns would be lower without the expense caps.
On April 30, 2021, Delaware Management Company
became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy. Performance prior to November 15, 2021 reflects the Fund’s former strategy;
its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
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| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 9.27%.
During the periods illustrated in this bar chart, Class A’s highest
quarterly return was 22.41%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -20.48%
for the quarter ended March 31,
2020. The maximum Class A
sales charge of 5.75%, which is normally
deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
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| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees or expenses | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
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| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Global Growth Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 9.27%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 9.27% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 22.41% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (20.48%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura International Core Equity Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura International Core Equity Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance. The
Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in
the future. The returns reflect
any expense caps in effect during these periods. The returns would be lower without the expense caps.
On April 30, 2021, Delaware Management Company
became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy. Performance prior to November 15, 2021 reflects the Fund’s former strategy;
its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
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| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 9.76%.
During the periods illustrated in this bar chart, Class A’s highest
quarterly return was 18.28%
for the quarter ended December
31, 2022, and its lowest
quarterly return was -24.49%
for the quarter ended March
31, 2020. The maximum Class
A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
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| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees or expenses | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura International Core Equity Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 9.76%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 9.76% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 18.28% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Dec. 31, 2022 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (24.49%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Large Cap Growth Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Large Cap Growth Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of -1.62%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 25.44%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -19.61%
for the quarter ended June
30, 2022.
The maximum Class A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If
this fee were included, the returns would be less than those shown. The average annual total returns in the table
below do include the sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
[1] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses, or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Large Cap Growth Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of -1.62%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | (1.62%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 25.44% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (19.61%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Jun. 30, 2022 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Mid Cap Growth Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Mid Cap Growth Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 4.99%.
During the periods illustrated in this bar chart, Class A’s highest
quarterly return was 37.07%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -21.85%
for the quarter ended June
30, 2022.
The maximum Class A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If
this fee were included, the returns would be less than those shown. The average annual total returns in the table
below do include the sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
[2] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses, or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Mid Cap Growth Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 4.99%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 4.99% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 37.07% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (21.85%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Jun. 30, 2022 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Mid Cap Income Opportunities Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Mid Cap Income Opportunities Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 9.01%.
During the periods illustrated in this bar chart, Class A’s highest
quarterly return was 23.59%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -29.52%
for the quarter ended March
31, 2020.
The maximum Class A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If
this fee were included, the returns would be less than those shown. The average annual total returns in the table
below do include the sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
[3] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses, or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Mid Cap Income Opportunities Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 9.01%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 9.01% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 23.59% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (29.52%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Smid Cap Core Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Smid Cap Core Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy. Performance prior to November 15, 2021 reflects the Fund’s former strategy;
its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 21.42%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 26.93%
for the quarter ended December
31, 2020, and its lowest
quarterly return was -29.00%
for the quarter ended March
31, 2020. The maximum Class
A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
[4] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses, or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Smid Cap Core Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 21.42%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 21.42% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 26.93% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Dec. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (29.00%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Small Cap Growth Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Small Cap Growth Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 21.87%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 27.88%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -21.70%
for the quarter ended June
30, 2022.
The maximum Class A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If
this fee were included, the returns would be less than those shown. The average annual total returns in the table
below do include the sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
[5] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses, or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Small Cap Growth Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 21.87%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 21.87% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 27.88% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (21.70%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Jun. 30, 2022 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Systematic Emerging Markets Equity Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Systematic Emerging Markets Equity Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance. The
Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in
the future. The returns reflect
any expense caps in effect during these periods. The returns would be lower without the expense caps.
On April 30, 2021, Delaware Management Company
became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy. Performance prior to November 15, 2021 reflects the Fund’s former strategy;
its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 24.01%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 27.23%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -23.93%
for the quarter ended March 31,
2020. The maximum Class A
sales charge of 5.75%, which is normally
deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees or expenses | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Systematic Emerging Markets Equity Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 24.01%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 24.01% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 27.23% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (23.93%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Climate Solutions Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Climate Solutions Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year
and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those
of a broad measure of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and
after taxes) is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during
these periods. The returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy; subsequently, effective July 29, 2022, the Fund repositioned into a climate solutions
fund. Performance prior to the Fund’s repositioning on July 29, 2022 reflects the Fund’s former strategies; its performance
may have differed if the Fund’s current
strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 15.63%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 38.84%
for the quarter ended December
31, 2020, and its lowest
quarterly return was -61.54%
for the quarter ended March
31, 2020. The maximum Class
A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees or expenses | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Climate Solutions Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 15.63%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 15.63% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 38.84% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Dec. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (61.54%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Natural Resources Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Natural Resources Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy. Performance prior to November 15, 2021 reflects the Fund’s former strategy;
its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 8.13%.
During the periods illustrated in this bar chart, Class A’s highest
quarterly return was 25.86%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -38.77%
for the quarter ended March
31, 2020.
The maximum Class A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If
this fee were included, the returns would be less than those shown. The average annual total returns in the table
below do include the sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Natural Resources Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 8.13%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 8.13% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 25.86% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (38.77%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Real Estate Securities Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Real Estate Securities Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective July 29, 2022, the Fund changed its
investment strategy. Performance prior to the Fund’s change of investment strategy on July 29, 2022 reflects
the Fund’s former strategy; its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 17.35%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 15.68%
for the quarter ended September
30, 2024, and its lowest
quarterly return was -21.73%
for the quarter ended March
31, 2020. The maximum Class
A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Real Estate Securities Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 17.35%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 17.35% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 15.68% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Sep. 30, 2024 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (21.73%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Science and Technology Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Science and Technology Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
![]() |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 43.50%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 28.28%
for the quarter ended June
30, 2025, and its lowest
quarterly return was -24.09%
for the quarter ended June
30, 2022.
The maximum Class A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If
this fee were included, the returns would be less than those shown. The average annual total returns in the table
below do include the sales charge.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Science and Technology Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 43.50%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 43.50% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 28.28% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (24.09%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Jun. 30, 2022 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Global Bond Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura Global Bond Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
Effective November 15, 2021, the Fund changed
its investment strategy. Performance prior to November 15, 2021 reflects the Fund’s former strategy;
its performance may have differed if the Fund’s current strategy had been in place.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
|
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| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
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| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of 1.19%.
During the periods illustrated in this bar chart, Class A’s highest
quarterly return was 9.39%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -6.60%
for the quarter ended March 31,
2020.
The maximum Class A sales charge of 4.50%,
which is normally deducted when you purchase shares, is not reflected in the highest/lowest quarterly
returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total returns in
the table below do include the sales charge.
|
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| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
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| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
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| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura Global Bond Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of 1.19%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 1.19% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 9.39% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (6.60%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura High Income Fund | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | How has Nomura High Income Fund performed? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] |
The
bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s
performance from year to year and the table
shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure
of market performance and an additional index with characteristics relevant to the Fund. The
Fund’s past performance (before and after taxes)
is not necessarily an indication of how the Fund will perform in the future.
The returns reflect any expense caps in effect during these periods. The
returns would be lower without the expense caps.
On April 30, 2021, Delaware Management
Company became the Fund’s investment manager. The returns shown from before April 30, 2021 are from the
Fund’s prior investment manager.
You may obtain the Fund’s most recently
available month-end performance by calling 800
523-1918 or by visiting our
website at nomuraassetmanagement.com/performance.
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| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year and the table shows how the Fund’s average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Calendar year-by-year total return (Class A) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart [Table] |
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| Bar Chart Closing [Text Block] |
As
of June
30, 2026, the Fund’s
Class A shares had a calendar year-to-date return of -0.76%.
During the periods illustrated in this bar chart, Class A’s
highest
quarterly return was 8.54%
for the quarter ended June
30, 2020, and its lowest
quarterly return was -15.83%
for the quarter ended March 31,
2020. The maximum Class A
sales charge of 4.50%, which is normally
deducted when you purchase shares, is not reflected in the highest/lowest
quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total
returns in the table below do include the
sales charge.
|
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| Performance Table Heading | Average annual total returns for periods ended December 31, 2025 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance [Table] |
|
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| Performance Table One Class of after Tax Shown [Text] | After-tax performance is presented only for Class A shares of the Fund. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Index No Deduction for Fees, Expenses, or Taxes [Text] | reflects no deduction for fees, expenses or taxes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Table Closing [Text Block] |
After-tax
performance is presented only for Class A shares of the Fund.
The after-tax returns for other Fund classes may vary.
Actual after-tax returns depend on the investor’s
individual tax situation and may differ from the returns shown. After-tax
returns are not relevant for shares held in tax-advantaged
investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The
after-tax returns shown are calculated using
the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact
of state and local taxes.
|
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| Performance Availability Website Address [Text] | nomuraassetmanagement.com/performance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Availability Phone [Text] | 800 523-1918 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nomura High Income Fund | A | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prospectus [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | As of June 30, 2026, the Fund’s Class A shares had a calendar year-to-date return of -0.76%. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | (0.76%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 8.54% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (15.83%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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