Investment Strategy	Nov. 30, 2025
Nomura Small Cap Core Fund - Class A, C, R, Institutional and R6 \| Nomura Small Cap Core Fund
Prospectus [Line Items]
Strategy [Heading]	What are the Fund’s principal investment strategies?
Strategy Narrative [Text Block]	The Fund invests primarily in stocks of small companies that its investment manager, Delaware Management Company (Manager), believes have a combination of attractive valuations, growth prospects, and strong cash flows. Under normal circumstances, at least 80% of the Fund’s net assets, plus the amount of any borrowings for investment purposes, will be in investments of small-capitalization companies (80% policy). The Fund considers small-capitalization companies to be companies within the market capitalization range of the Russell 2000^® Index at the time of purchase. The Fund’s 80% policy is nonfundamental and may be changed without shareholder approval. Fund shareholders would be given at least 60 days’ notice prior to any such change.
Strategy Portfolio Concentration [Text]	The Fund invests primarily in stocks of small companies that its investment manager, Delaware Management Company (Manager), believes have a combination of attractive valuations, growth prospects, and strong cash flows. Under normal circumstances, at least 80% of the Fund’s net assets, plus the amount of any borrowings for investment purposes, will be in investments of small-capitalization companies (80% policy).
Nomura Small Cap Value Fund - Class A, C, R, Institutional and R6 \| Nomura Small Cap Value Fund
Prospectus [Line Items]
Strategy [Heading]	What are the Fund’s principal investment strategies?
Strategy Narrative [Text Block]	The Fund invests primarily in investments of small companies whose stock prices, in the portfolio managers’ opinion, appear low relative to their underlying value or future potential. Among other factors, the Fund’s investment manager, Delaware Management Company (Manager), considers the financial strength of a company, its management, the prospects for its industry, and any anticipated changes within the company that might suggest a more favorable outlook going forward. The Manager focuses on free cash flow in its individual stock selection, seeking companies that it believes have a sustainable ability to buy back shares, lower debt, and/or increase or initiate dividends. Under normal circumstances, at least 80% of the Fund’s net assets, plus the amount of any borrowings for investment purposes, will be in investments of small-capitalization companies (80% policy). The Fund considers small-capitalization companies to be companies with a market capitalization generally less than 3.5 times the dollar-weighted, median market capitalization of the Russell 2000^® Index at the time of purchase. The Fund may invest up to 15% of its net assets in real estate investment trusts (REITs). The Fund’s 80% policy is nonfundamental and may be changed without shareholder approval. Fund shareholders would be given at least 60 days’ notice prior to any such change.
Strategy Portfolio Concentration [Text]	The Fund invests primarily in investments of small companies whose stock prices, in the portfolio managers’ opinion, appear low relative to their underlying value or future potential.
Nomura Wealth Builder Fund - Class A, C, R, Institutional and R6 \| Nomura Wealth Builder Fund
Prospectus [Line Items]
Strategy [Heading]	What are the Fund’s principal investment strategies?
Strategy Narrative [Text Block]	The Fund invests primarily in income-generating securities (debt and equity), which may include equity securities of large, well-established companies, and debt securities, including high yield (junk) bonds, high-risk corporate bonds, investment grade fixed income securities, convertible securities, and US government securities. Under normal circumstances, at least 50% of the Fund’s total assets will be invested in income-generating equity securities, including real estate investment trusts (REITs), convertible securities, and exchange-traded funds (ETFs). While debt securities may comprise up to 50% of the Fund’s total assets, no more than 45% of the Fund’s total assets will be invested in high yield, high-risk debt securities. No more than 25% of the Fund’s total assets will be invested in any one industry sector nor, as to 75% of the Fund’s total assets, will more than 5% be invested in securities of any one issuer. The Fund may invest up to 30% of its total assets in foreign equity and debt securities. The Fund will not, however, invest more than 10% of its total assets in securities of issuers principally located or principally operating in markets of emerging countries. The Manager uses a dynamic asset-allocation framework to determine the proportion of the Fund’s assets that will be allocated to the various asset classes noted above, based on the market assessment and portfolio risk contribution for such asset classes. In connection with this dynamic asset-allocation framework, the Manager will also manage a tactical / completion sleeve and such sleeve will typically vary from 0% to 20% of the Fund’s total assets and primarily hold derivatives and ETFs. If applicable, the derivatives and ETFs within the tactical / completion sleeve will also be counted towards the asset classes noted above. The Fund may use a wide range of derivative instruments, typically including forward foreign currency contracts, options, futures contracts, options on futures contracts, and credit default swaps. The Fund will use derivatives for both hedging and non-hedging purposes; as a substitute for purchasing or selling securities; and to manage the Fund’s portfolio characteristics. For example, the Fund may invest in: futures and options to manage duration and for defensive purposes, such as to protect gains or hedge against potential losses in the portfolio without actually selling a security, or to stay fully invested; forward foreign currency contracts to manage foreign currency exposure; and credit default swaps to hedge against a credit event, to gain exposure to certain securities or markets, or to enhance total return. At times, the Fund may invest in a wholly-owned company acting as an investment vehicle for the Fund, in order to effect certain investments consistent with the Fund’s investment objectives (Subsidiary). The Fund’s investment in the Subsidiary is expected to provide the Fund with exposure to certain investments in accordance with the limits of the federal tax laws. The Fund complies with the provisions of the Investment Company Act of 1940 (1940 Act) governing investment policies, capital structure and leverage on an aggregate basis with the Subsidiary. The Subsidiary complies with the 1940 Act’s provisions relating to affiliated transactions and custody of assets. Investment in the Fund does not in any way provide an indication of future performance or a guarantee of positive returns.
Strategy Portfolio Concentration [Text]	The Fund invests primarily in income-generating securities (debt and equity), which may include equity securities of large, well-established companies, and debt securities, including high yield (junk) bonds, high-risk corporate bonds, investment grade fixed income securities, convertible securities, and US government securities.