485BPOS

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM N-1A

File No. 002-95928
File No. 811-04547

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	/X/
Pre-Effective Amendment No. _____	/   /
Post-Effective Amendment No.    61	/X/
	and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940	/X/
Amendment No.    61

(Check appropriate box or boxes.)

VOYAGEUR MUTUAL FUNDS III

(Exact Name of Registrant as Specified in Charter)

2005 Market Street, Philadelphia, Pennsylvania	19103-7094
(Address of Principal Executive Offices)	(Zip Code)

	Registrant's Telephone Number, including Area Code:	(800) 523-1918
David F. Connor, Esq., 2005 Market Street, Philadelphia, PA 19103-7094
(Name and Address of Agent for Service)

It is proposed that this filing will become effective (check appropriate box):

/X/	immediately upon filing pursuant to paragraph (b)
/   /	on (date) pursuant to paragraph (b)
/   /	60 days after filing pursuant to paragraph (a)(1)
/   /	on (date) pursuant to paragraph (a)(1)
/   /	75 days after filing pursuant to paragraph (a)(2)
/   /	on (date) pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

/   /       this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements for effectiveness of this Registration Statement under Rule 485(b) under the Securities Act of 1933 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Philadelphia and Commonwealth of Pennsylvania on this 18th day of September, 2013.

VOYAGEUR MUTUAL FUNDS III
By:	/s/ Patrick P. Coyne
	Patrick P. Coyne
Chairman/President/Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities and on the dates indicated:

Signature		Title	Date
/s/ Patrick P. Coyne		Chairman/President/Chief Executive Officer	September 18, 2013
Patrick P. Coyne		(Principal Executive Officer) and Trustee
Thomas L. Bennett	*	Trustee	September 18, 2013
Thomas L. Bennett
Joseph W. Chow	*	Trustee	September 18, 2013
Joseph W. Chow
John A. Fry	*	Trustee	September 18, 2013
John A. Fry
Anthony D. Knerr	*	Trustee	September 18, 2013
Anthony D. Knerr
Lucinda S. Landreth	*	Trustee	September 18, 2013
Lucinda S. Landreth
Frances A. Sevilla-Sacasa	*	Trustee	September 18, 2013
Frances A. Sevilla-Sacasa
Thomas K. Whitford	*	Trustee	September 18, 2013
Thomas K. Whitford
Janet L. Yeomans	*	Trustee	September 18, 2013
Janet L. Yeomans
J. Richard Zecher	*	Trustee	September 18, 2013
J. Richard Zecher
Richard Salus	*	Senior Vice President/Chief Financial Officer	September 18, 2013
Richard Salus		(Principal Financial Officer)

*By:	/s/ Patrick P. Coyne
Patrick P. Coyne as Attorney-in-Fact for each of the persons indicated (Pursuant to Powers of Attorney previously filed)

INDEX TO EXHIBITS
(Voyageur Mutual Funds III N-1A)

Exhibit No.	Exhibit
EX-1-101.INS	XBRL Instance Document
EX-1-101.SCH	XBRL Taxonomy Extension Schema Document
EX-1-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-1-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-1-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

XML

Shareholder Fees (dei_DocumentInformationDocumentAxis)	0 Months Ended
	Aug. 28, 2013
(Delaware Select Growth Fund) | Class A
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	5.75%
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none
(Delaware Select Growth Fund) | Class B
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	4.00%	[1]
(Delaware Select Growth Fund) | Class C
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	1.00%	[1]
(Delaware Select Growth Fund) | Class R
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none
(Delaware Select Growth Fund) | Institutional Class
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none
(Delaware Large Cap Core Fund) | Class A
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	5.75%
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none
(Delaware Large Cap Core Fund) | Class C
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	1.00%	[2]
(Delaware Large Cap Core Fund) | Institutional Class
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none
(Delaware Large Cap Core Fund) | Class R
Shareholder Fees:
Maximum sales charge (load) imposed on purchases as a percentage of offering price	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none

[1] If you redeem Class B shares during the first year after you buy them, you will pay a contingent deferred sales charge (CDSC) of 4.00%, which declines to 3.25% during the second year, 2.75% during the third year, 2.25% during the fourth and fifth years, 1.50% during the sixth year, and 0% thereafter. Class C shares redeemed within one year of purchase are subject to a 1.00% CDSC.

[2] Class C shares redeemed within one year of purchase are subject to a 1.00% contingent deferred sales charge (CDSC).

XML

Expense Example (dei_DocumentInformationDocumentAxis, USD $)	0 Months Ended
	Aug. 28, 2013
(Delaware Select Growth Fund) | Class A
Expense Example:
Expense Example, with Redemption, 1 Year	$ 697
Expense Example, with Redemption, 3 Years	955
Expense Example, with Redemption, 5 Years	1,232
Expense Example, with Redemption, 10 Years	2,021
(Delaware Select Growth Fund) | Class B
Expense Example:
Expense Example, with Redemption, 1 Year	605
Expense Example, with Redemption, 3 Years	909
Expense Example, with Redemption, 5 Years	1,313
Expense Example, with Redemption, 10 Years	2,155
(Delaware Select Growth Fund) | Class C
Expense Example:
Expense Example, with Redemption, 1 Year	305
Expense Example, with Redemption, 3 Years	634
Expense Example, with Redemption, 5 Years	1,088
Expense Example, with Redemption, 10 Years	2,348
(Delaware Select Growth Fund) | Class R
Expense Example:
Expense Example, with Redemption, 1 Year	155
Expense Example, with Redemption, 3 Years	501
Expense Example, with Redemption, 5 Years	872
Expense Example, with Redemption, 10 Years	1,914
(Delaware Select Growth Fund) | Institutional Class
Expense Example:
Expense Example, with Redemption, 1 Year	104
Expense Example, with Redemption, 3 Years	325
Expense Example, with Redemption, 5 Years	563
Expense Example, with Redemption, 10 Years	1,248
(Delaware Large Cap Core Fund) | Class A
Expense Example:
Expense Example, with Redemption, 1 Year	797
Expense Example, with Redemption, 3 Years	1,258
Expense Example, with Redemption, 5 Years	1,744
Expense Example, with Redemption, 10 Years	3,078
(Delaware Large Cap Core Fund) | Class C
Expense Example:
Expense Example, with Redemption, 1 Year	410
Expense Example, with Redemption, 3 Years	948
Expense Example, with Redemption, 5 Years	1,611
Expense Example, with Redemption, 10 Years	3,383
(Delaware Large Cap Core Fund) | Institutional Class
Expense Example:
Expense Example, with Redemption, 1 Year	210
Expense Example, with Redemption, 3 Years	649
Expense Example, with Redemption, 5 Years	1,114
Expense Example, with Redemption, 10 Years	2,400
(Delaware Large Cap Core Fund) | Class R
Expense Example:
Expense Example, with Redemption, 1 Year	270
Expense Example, with Redemption, 3 Years	829
Expense Example, with Redemption, 5 Years	1,415
Expense Example, with Redemption, 10 Years	$ 3,003

XML

(Delaware Large Cap Core Fund)

What is the Fund's investment objective?

Delaware Large Cap Core Fund seeks long-term capital appreciation.

What are the Fund's fees and expenses?

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Investments® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

The Fund's investment manager, Delaware Management Company (Manager), is voluntarily waiving its investment advisory fees and/or paying expenses (excluding any 12b-1 fees, taxes, interest, short sale and dividend interest expenses, brokerage fees, certain insurance costs, and nonroutine expenses or costs, including, but not limited to, those relating to reorganizations, litigation, conducting shareholder meetings, and liquidations) to the extent necessary to prevent total annual Fund operating expenses from exceeding 0.95% of the Fund's average daily net assets from August 28, 2013 until such time as the voluntary expense cap is discontinued. In addition, the Fund's distributor, Delaware Distributor, L.P. (Distributor), has voluntarily agreed to waive all 12b-1 fees. After giving effect to the Manager's and Distributor's voluntary waivers, the total net annual Fund's operating expenses for the Fund's Class A, Class C, Class R, and Institutional Class shares are 0.95%. The Manager's and Distributor's waivers and/or reimbursements may be discontinued at any time because they are voluntary.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees (Delaware Large Cap Core Fund)	Class A	Class C		Class R	Institutional Class
Maximum sales charge (load) imposed on purchases as a percentage of offering price	5.75%	none		none	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none	1.00%	[1]	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses (Delaware Large Cap Core Fund)	Class A	Class C	Class R	Institutional Class
Management fees	0.65%	0.65%	0.65%	0.65%
Distribution and service (12b-1) fees	0.25%	1.00%	0.60%	none
Other expenses	1.42%	1.42%	1.42%	1.42%
Total annual fund operating expenses	2.32%	3.07%	2.67%	2.07%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (Delaware Large Cap Core Fund) (USD $)	1 Year	3 Years	5 Years	10 Years
Class A	797	1,258	1,744	3,078
Class C	410	948	1,611	3,383
Class R	270	829	1,415	3,003
Institutional Class	210	649	1,114	2,400

Expense Example, No Redemption (Delaware Large Cap Core Fund) (USD $)	1 Year	3 Years	5 Years	10 Years
Class C	310	948	1,611	3,383

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 21% of the average value of its portfolio.

What are the Fund's principal investment strategies?

The Fund's investment manager, Delaware Management Company (Manager), will invest the Fund's assets primarily in common stocks of large companies that the Manager believes have a combination of attractive valuations, growth prospects, and strong cash flows. Under normal circumstances, the Fund will invest at least 80% of its net assets in securities of large-capitalization companies (80% policy). The Fund currently defines large-capitalization companies as those that, at the time of investment, have market capitalizations within the range of market capitalizations of companies in the S&P 500® Index. While the market capitalization of companies in the S&P 500 Index ranged from approximately $2 billion to $402 billion as of June 30, 2013, the Fund will normally invest in common stock of companies with market capitalizations of at least $2 billion at the time of purchase. The Fund's 80% policy can be changed without shareholder approval. However, shareholders would be given at least 60 days' notice prior to any change.

What are the principal risks of investing in the Fund?

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio. Principal risks include:

Investments not guaranteed by Delaware Management Company (Manager) or its affiliates — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Foreign risk — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Futures and options risk — The possibility that a fund may experience a loss if it employs an options or futures strategy related to a security or a market index and that security or index moves in the opposite direction from what the portfolio manager anticipated. Futures and options also involve additional expenses (such as the payment of premiums), which could reduce any benefit or increase any loss that a fund gains from using the strategy.

Counterparty risk — The risk that a counterparty to a derivative contract (such as a futures or options contract) or a repurchase agreement may fail to perform its obligations under the contract or agreement due to financial difficulties (such as a bankruptcy or reorganization).

Liquidity risk — The possibility that securities cannot be readily sold within seven days at approximately the price at which a portfolio has valued them.

Government and regulatory risk — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

How has Delaware Large Cap Core Fund performed?

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns for the 1-year, 5-year, and lifetime 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 it will perform in the future. The returns reflect expense caps in effect during these periods. The returns would be lower without the expense caps. You may obtain the Fund's most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

Year-by-year total return (Class A)

As of June 30, 2013, the Fund's Class A shares had a calendar year-to-date return of 12.31%. During the periods illustrated in this bar chart, Class A's highest quarterly return was 15.91% for the quarter ended June 30, 2009 and its lowest quarterly return was -21.71% for the quarter ended Dec. 31, 2008. 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 sales charge were included, the returns would be less than those shown. The average annual returns in the table below do include the sales charge.

Average annual total returns for periods ended December 31, 2012

Average Annual Total Returns (Delaware Large Cap Core Fund)	Label	1 Year	5 Years	Lifetime
Class A	Lifetime (8/31/06 to 12/31/12)	8.48%	(0.57%)	1.96%
Class A return after taxes on distributions	Lifetime (8/31/06 to 12/31/12)	8.33%	(0.71%)	1.68%
Class A return after taxes on distributions and sale of Fund shares	Lifetime (8/31/06 to 12/31/12)	5.71%	(0.51%)	1.61%
Class C	Lifetime (8/31/06 to 12/31/12)
Class R	Lifetime (8/31/06 to 12/31/12)
Institutional Class	Lifetime (8/31/06 to 12/31/12)	15.05%	0.61%	2.92%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	Lifetime (8/31/06 to 12/31/12)	16.00%	1.66%	3.63%

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-deferred 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.

[1] Class C shares redeemed within one year of purchase are subject to a 1.00% contingent deferred sales charge (CDSC).

XML

(Delaware Select Growth Fund)

What is the Fund's investment objective?

Delaware Select Growth Fund seeks long-term capital appreciation.

What are the Fund's fees and expenses?

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Investments® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

Shareholder fees (fees paid directly from your investment)

Shareholder Fees (Delaware Select Growth Fund)	Class A	Class B		Class C		Class R	Institutional Class
Maximum sales charge (load) imposed on purchases as a percentage of offering price	5.75%	none		none		none	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none	4.00%	[1]	1.00%	[1]	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses (Delaware Select Growth Fund)	Class A	Class B	Class C	Class R		Institutional Class
Management fees	0.73%	0.73%	0.73%	0.73%		0.73%
Distribution and service (12b-1) fees	0.25%	1.00%	1.00%	0.60%		none
Other expenses	0.29%	0.29%	0.29%	0.29%		0.29%
Total annual fund operating expenses	1.27%	2.02%	2.02%	1.62%		1.02%
Fee waivers and expense reimbursements				(0.10%)	[1]
Total annual fund operating expenses after fee waivers and expense reimbursements	1.27%	2.02%	2.02%	1.52%		1.02%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. For Class R shares, this example reflects the net operating expenses with the Rule 12b-1 fee waiver for the contractual period and the total operating expenses without waivers for years 2 through 10. For Class A, Class B, Class C, and Institutional Class shares, this example assumes that the Fund's total operating expenses remain unchanged in each of the periods shown. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (Delaware Select Growth Fund) (USD $)	1 Year	3 Years	5 Years	10 Years
Class A	697	955	1,232	2,021
Class B	605	909	1,313	2,155
Class C	305	634	1,088	2,348
Class R	155	501	872	1,914
Institutional Class	104	325	563	1,248

Expense Example, No Redemption (Delaware Select Growth Fund) (USD $)	1 Year	3 Years	5 Years	10 Years
Class B	205	634	1,088	2,155
Class C	205	634	1,088	2,348

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 38% of the average value of its portfolio.

What are the Fund's principal investment strategies?

The Fund invests primarily in common stocks of companies that we believe have long-term capital appreciation potential and are expected to grow faster than the U.S. economy. The portfolio managers will consider companies of any size or market capitalization. Using a bottom-up approach, the portfolio managers seek to select securities they believe have large end-market potential or dominance of a profitable niche market, dominant business models, and strong free cash flow generation that are attractively priced compared to the intrinsic value of the securities. They also consider a company's operational efficiencies, management's plans for capital allocation, and the company's shareholder orientation. Holdings are generally sold for the following reasons: a better idea is found (that is, the stock is "crowded out" of the portfolio); an unexpected, negative fundamental change, including change in investment strategy; the holding's valuation becomes stretched past fair value; or portfolio construction considerations.

What are the principal risks of investing in the Fund?

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio. Principal risks include:

Investments not guaranteed by Delaware Management Company (Manager) or its affiliates — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Issuer concentration risk — The portfolio generally holds 40 to 60 securities although, from time to time, the portfolio may hold fewer or more securities depending on our assessment of the investment opportunities available. This allows us to focus on the potential of those particular issuers, but it also means that the Fund may be more volatile than those funds that hold a greater number of securities.

Company size risk — The risk that prices of small- and medium-sized companies may be more volatile than those of larger companies because of limited financial resources or dependence on narrow product lines.

Liquidity risk — The possibility that securities cannot be readily sold within seven days at approximately the price at which a portfolio has valued them.

Foreign risk — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Currency risk — The risk that the value of a portfolio's investments may be negatively affected by changes in foreign currency exchange rates.

Interest rate risk — The risk that securities will decrease in value if interest rates rise. The risk is generally associated with bonds; however, because small- and medium-sized companies and companies in the real estate sector often borrow money to finance their operations, they may be adversely affected by rising interest rates.

Counterparty risk — The risk that a counterparty to a derivative contract (such as a swap, futures, or options contract) or a repurchase agreement may fail to perform its obligations under the contract or agreement due to financial difficulties (such as a bankruptcy or reorganization).

Government and regulatory risk — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

How has Delaware Select Growth Fund performed?

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns for the 1-, 5-, and 10-year or lifetime 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 it will perform in the future. The returns reflect expense caps in effect during certain of these periods. The returns would be lower without the expense caps. You may obtain the Fund's most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

Year-by-year total return (Class A)

As of June 30, 2013, the Fund's Class A shares had a calendar year-to-date return of 9.22%. During the periods illustrated in this bar chart, Class A's highest quarterly return was 23.21% for the quarter ended June 30, 2009 and its lowest quarterly return was -24.96% for the quarter ended December 31, 2008. 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 sales charge were included, the returns would be less than those shown. The average annual returns in the table below do include the sales charge.

Average annual total returns for periods ended December 31, 2012

Average Annual Total Returns (Delaware Select Growth Fund)	Label	1 Year	5 Years	10 Years	Lifetime
Class A		8.68%	5.20%	9.58%
Class A return after taxes on distributions		8.68%	5.20%	9.58%
Class A return after taxes on distributions and sale of Fund shares		5.64%	4.49%	8.56%
Class B		10.45%	5.30%	9.57%
Class C		13.48%	5.66%	9.42%
Class R	(lifetime:6/2/03–12/31/12)	15.02%	6.18%		8.13%
Institutional Class		15.60%	6.73%	10.52%
Russell 3000® Growth Index (reflects no deduction for fees, expenses, or taxes)		15.20%	3.15%	7.69%

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-deferred 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.

[1] If you redeem Class B shares during the first year after you buy them, you will pay a contingent deferred sales charge (CDSC) of 4.00%, which declines to 3.25% during the second year, 2.75% during the third year, 2.25% during the fourth and fifth years, 1.50% during the sixth year, and 0% thereafter. Class C shares redeemed within one year of purchase are subject to a 1.00% CDSC.

[1] The Fund's distributor, Delaware Distributors, L.P. (Distributor), has contracted to limit the Class R shares' 12b-1 fees to no more than 0.50% of the Fund's average daily net assets from August 28, 2013 through February 27, 2015 or, if longer, until the Fund is offered to all new investors (as described under "Purchase and redemption of Fund shares").

XML

Expense Example, No Redemption (dei_DocumentInformationDocumentAxis, USD $)	0 Months Ended
	Aug. 28, 2013
(Delaware Select Growth Fund) | Class B
Expense Example, No Redemption:
Expense Example, No Redemption, 1 Year	$ 205
Expense Example, No Redemption, 3 Years	634
Expense Example, No Redemption, 5 Years	1,088
Expense Example, No Redemption, 10 Years	2,155
(Delaware Select Growth Fund) | Class C
Expense Example, No Redemption:
Expense Example, No Redemption, 1 Year	205
Expense Example, No Redemption, 3 Years	634
Expense Example, No Redemption, 5 Years	1,088
Expense Example, No Redemption, 10 Years	2,348
(Delaware Large Cap Core Fund) | Class C
Expense Example, No Redemption:
Expense Example, No Redemption, 1 Year	310
Expense Example, No Redemption, 3 Years	948
Expense Example, No Redemption, 5 Years	1,611
Expense Example, No Redemption, 10 Years	$ 3,383

XML

Annual Total Returns (dei_DocumentInformationDocumentAxis, Class A)	0 Months Ended
	Aug. 28, 2013
(Delaware Select Growth Fund) | Class A
Bar Chart Table:
Annual Return 2003	37.97%
Annual Return 2004	7.98%
Annual Return 2005	17.21%
Annual Return 2006	1.28%
Annual Return 2007	9.62%
Annual Return 2008	(44.30%)
Annual Return 2009	56.96%
Annual Return 2010	26.25%
Annual Return 2011	7.42%
Annual Return 2012	15.31%
(Delaware Large Cap Core Fund) | Class A
Bar Chart Table:
Annual Return 2007	7.73%
Annual Return 2008	(36.77%)
Annual Return 2009	23.62%
Annual Return 2010	11.93%
Annual Return 2011	2.41%
Annual Return 2012	15.05%

XML

Annual Fund Operating Expenses (dei_DocumentInformationDocumentAxis)	0 Months Ended
	Aug. 28, 2013
(Delaware Select Growth Fund) | Class A
Operating Expenses:
Management fees	0.73%
Distribution and service (12b-1) fees	0.25%
Other expenses	0.29%
Total annual fund operating expenses	1.27%
Fee waivers and expense reimbursements
Total annual fund operating expenses after fee waivers and expense reimbursements	1.27%
(Delaware Select Growth Fund) | Class B
Operating Expenses:
Management fees	0.73%
Distribution and service (12b-1) fees	1.00%
Other expenses	0.29%
Total annual fund operating expenses	2.02%
Fee waivers and expense reimbursements
Total annual fund operating expenses after fee waivers and expense reimbursements	2.02%
(Delaware Select Growth Fund) | Class C
Operating Expenses:
Management fees	0.73%
Distribution and service (12b-1) fees	1.00%
Other expenses	0.29%
Total annual fund operating expenses	2.02%
Fee waivers and expense reimbursements
Total annual fund operating expenses after fee waivers and expense reimbursements	2.02%
(Delaware Select Growth Fund) | Class R
Operating Expenses:
Management fees	0.73%
Distribution and service (12b-1) fees	0.60%
Other expenses	0.29%
Total annual fund operating expenses	1.62%
Fee waivers and expense reimbursements	(0.10%)	[1]
Total annual fund operating expenses after fee waivers and expense reimbursements	1.52%
(Delaware Select Growth Fund) | Institutional Class
Operating Expenses:
Management fees	0.73%
Distribution and service (12b-1) fees	none
Other expenses	0.29%
Total annual fund operating expenses	1.02%
Fee waivers and expense reimbursements
Total annual fund operating expenses after fee waivers and expense reimbursements	1.02%
(Delaware Large Cap Core Fund) | Class A
Operating Expenses:
Management fees	0.65%
Distribution and service (12b-1) fees	0.25%
Other expenses	1.42%
Total annual fund operating expenses	2.32%
(Delaware Large Cap Core Fund) | Class C
Operating Expenses:
Management fees	0.65%
Distribution and service (12b-1) fees	1.00%
Other expenses	1.42%
Total annual fund operating expenses	3.07%
(Delaware Large Cap Core Fund) | Institutional Class
Operating Expenses:
Management fees	0.65%
Distribution and service (12b-1) fees	none
Other expenses	1.42%
Total annual fund operating expenses	2.07%
(Delaware Large Cap Core Fund) | Class R
Operating Expenses:
Management fees	0.65%
Distribution and service (12b-1) fees	0.60%
Other expenses	1.42%
Total annual fund operating expenses	2.67%

[1] The Fund's distributor, Delaware Distributors, L.P. (Distributor), has contracted to limit the Class R shares' 12b-1 fees to no more than 0.50% of the Fund's average daily net assets from August 28, 2013 through February 27, 2015 or, if longer, until the Fund is offered to all new investors (as described under "Purchase and redemption of Fund shares").

XML

Average Annual Total Returns (dei_DocumentInformationDocumentAxis)	0 Months Ended
	Aug. 28, 2013
(Delaware Select Growth Fund) | Russell 3000® Growth Index (reflects no deduction for fees, expenses, or taxes)
Average Annual Return:
1 Year	15.20%
5 Years	3.15%
10 Years	7.69%
(Delaware Select Growth Fund) | Class A
Average Annual Return:
1 Year	8.68%
5 Years	5.20%
10 Years	9.58%
(Delaware Select Growth Fund) | Class A | return after taxes on distributions
Average Annual Return:
1 Year	8.68%
5 Years	5.20%
10 Years	9.58%
(Delaware Select Growth Fund) | Class A | return after taxes on distributions and sale of Fund shares
Average Annual Return:
1 Year	5.64%
5 Years	4.49%
10 Years	8.56%
(Delaware Select Growth Fund) | Class B
Average Annual Return:
1 Year	10.45%
5 Years	5.30%
10 Years	9.57%
(Delaware Select Growth Fund) | Class C
Average Annual Return:
1 Year	13.48%
5 Years	5.66%
10 Years	9.42%
(Delaware Select Growth Fund) | Class R
Average Annual Return:
Label	(lifetime:6/2/03–12/31/12)
1 Year	15.02%
5 Years	6.18%
Lifetime	8.13%
(Delaware Select Growth Fund) | Institutional Class
Average Annual Return:
1 Year	15.60%
5 Years	6.73%
10 Years	10.52%
(Delaware Large Cap Core Fund) | S&P 500 Index (reflects no deduction for fees, expenses or taxes)
Average Annual Return:
Label	Lifetime (8/31/06 to 12/31/12)
1 Year	16.00%
5 Years	1.66%
Lifetime	3.63%
(Delaware Large Cap Core Fund) | Class A
Average Annual Return:
Label	Lifetime (8/31/06 to 12/31/12)
1 Year	8.48%
5 Years	(0.57%)
Lifetime	1.96%
(Delaware Large Cap Core Fund) | Class A | return after taxes on distributions
Average Annual Return:
Label	Lifetime (8/31/06 to 12/31/12)
1 Year	8.33%
5 Years	(0.71%)
Lifetime	1.68%
(Delaware Large Cap Core Fund) | Class A | return after taxes on distributions and sale of Fund shares
Average Annual Return:
Label	Lifetime (8/31/06 to 12/31/12)
1 Year	5.71%
5 Years	(0.51%)
Lifetime	1.61%
(Delaware Large Cap Core Fund) | Class C
Average Annual Return:
Label	Lifetime (8/31/06 to 12/31/12)
1 Year
5 Years
Lifetime
(Delaware Large Cap Core Fund) | Institutional Class
Average Annual Return:
Label	Lifetime (8/31/06 to 12/31/12)
1 Year	15.05%
5 Years	0.61%
Lifetime	2.92%
(Delaware Large Cap Core Fund) | Class R
Average Annual Return:
Label	Lifetime (8/31/06 to 12/31/12)
1 Year
5 Years
Lifetime

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Document Type

dei_DocumentType

485BPOS

Document Period End Date

dei_DocumentPeriodEndDate

Apr. 30, 2013

Registrant Name

dei_EntityRegistrantName

VOYAGEUR MUTUAL FUNDS III

Central Index Key

dei_EntityCentralIndexKey

0000763749

Amendment Flag

dei_AmendmentFlag

false

Document Creation Date

dei_DocumentCreationDate

Aug. 28, 2013

Document Effective Date

dei_DocumentEffectiveDate

Aug. 28, 2013

Prospectus Date

rr_ProspectusDate

Aug. 28, 2013

(Delaware Select Growth Fund)

Risk/Return:

rr_RiskReturnAbstract

Objective [Heading]

rr_ObjectiveHeading

What is the Fund's investment objective?

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Delaware Select Growth Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

What are the Fund's fees and expenses?

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Investments® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 38% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

38.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Investments® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

50,000

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. For Class R shares, this example reflects the net operating expenses with the Rule 12b-1 fee waiver for the contractual period and the total operating expenses without waivers for years 2 through 10. For Class A, Class B, Class C, and Institutional Class shares, this example assumes that the Fund's total operating expenses remain unchanged in each of the periods shown. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

What are the Fund's principal investment strategies?

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in common stocks of companies that we believe have long-term capital appreciation potential and are expected to grow faster than the U.S. economy. The portfolio managers will consider companies of any size or market capitalization. Using a bottom-up approach, the portfolio managers seek to select securities they believe have large end-market potential or dominance of a profitable niche market, dominant business models, and strong free cash flow generation that are attractively priced compared to the intrinsic value of the securities. They also consider a company's operational efficiencies, management's plans for capital allocation, and the company's shareholder orientation. Holdings are generally sold for the following reasons: a better idea is found (that is, the stock is "crowded out" of the portfolio); an unexpected, negative fundamental change, including change in investment strategy; the holding's valuation becomes stretched past fair value; or portfolio construction considerations.

Risk [Heading]

rr_RiskHeading

What are the principal risks of investing in the Fund?

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio. Principal risks include:

Investments not guaranteed by Delaware Management Company (Manager) or its affiliates — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Issuer concentration risk — The portfolio generally holds 40 to 60 securities although, from time to time, the portfolio may hold fewer or more securities depending on our assessment of the investment opportunities available. This allows us to focus on the potential of those particular issuers, but it also means that the Fund may be more volatile than those funds that hold a greater number of securities.

Company size risk — The risk that prices of small- and medium-sized companies may be more volatile than those of larger companies because of limited financial resources or dependence on narrow product lines.

Liquidity risk — The possibility that securities cannot be readily sold within seven days at approximately the price at which a portfolio has valued them.

Foreign risk — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Currency risk — The risk that the value of a portfolio's investments may be negatively affected by changes in foreign currency exchange rates.

Interest rate risk — The risk that securities will decrease in value if interest rates rise. The risk is generally associated with bonds; however, because small- and medium-sized companies and companies in the real estate sector often borrow money to finance their operations, they may be adversely affected by rising interest rates.

Counterparty risk — The risk that a counterparty to a derivative contract (such as a swap, futures, or options contract) or a repurchase agreement may fail to perform its obligations under the contract or agreement due to financial difficulties (such as a bankruptcy or reorganization).

Government and regulatory risk — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

Risk Lose Money [Text]

rr_RiskLoseMoney

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

How has Delaware Select Growth Fund performed?

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns for the 1-, 5-, and 10-year or lifetime 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 it will perform in the future. The returns reflect expense caps in effect during certain of these periods. The returns would be lower without the expense caps. You may obtain the Fund's most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800 523-1918

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

delawareinvestments.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Year-by-year total return (Class A)

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

As of June 30, 2013, the Fund's Class A shares had a calendar year-to-date return of 9.22%. During the periods illustrated in this bar chart, Class A's highest quarterly return was 23.21% for the quarter ended June 30, 2009 and its lowest quarterly return was -24.96% for the quarter ended December 31, 2008. 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 sales charge were included, the returns would be less than those shown. The average annual returns in the table below do include the sales charge.

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns for periods ended December 31, 2012

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

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

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns are not relevant for shares held in tax-deferred investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs).

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax performance is presented only for Class A shares of the Fund.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

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-deferred 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.

(Delaware Select Growth Fund) | Russell 3000® Growth Index (reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

15.20%

5 Years

rr_AverageAnnualReturnYear05

3.15%

10 Years

rr_AverageAnnualReturnYear10

7.69%

(Delaware Select Growth Fund) | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.73%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.29%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.27%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

1.27%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

697

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

955

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,232

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,021

Annual Return 2003

rr_AnnualReturn2003

37.97%

Annual Return 2004

rr_AnnualReturn2004

7.98%

Annual Return 2005

rr_AnnualReturn2005

17.21%

Annual Return 2006

rr_AnnualReturn2006

1.28%

Annual Return 2007

rr_AnnualReturn2007

9.62%

Annual Return 2008

rr_AnnualReturn2008

(44.30%)

Annual Return 2009

rr_AnnualReturn2009

56.96%

Annual Return 2010

rr_AnnualReturn2010

26.25%

Annual Return 2011

rr_AnnualReturn2011

7.42%

Annual Return 2012

rr_AnnualReturn2012

15.31%

Year to Date Return, Label

rr_YearToDateReturnLabel

As of June 30, 2013, the Fund's Class A shares had a calendar year-to-date return of 9.22%

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jun. 30, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

9.22%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Class A's highest quarterly return was 23.21% for the quarter ended June 30, 2009

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

23.21%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest quarterly return was -24.96% for the quarter ended December 31, 2008

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(24.96%)

1 Year

rr_AverageAnnualReturnYear01

8.68%

5 Years

rr_AverageAnnualReturnYear05

5.20%

10 Years

rr_AverageAnnualReturnYear10

9.58%

(Delaware Select Growth Fund) | Class A | return after taxes on distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.68%

5 Years

rr_AverageAnnualReturnYear05

5.20%

10 Years

rr_AverageAnnualReturnYear10

9.58%

(Delaware Select Growth Fund) | Class A | return after taxes on distributions and sale of Fund shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.64%

5 Years

rr_AverageAnnualReturnYear05

4.49%

10 Years

rr_AverageAnnualReturnYear10

8.56%

(Delaware Select Growth Fund) | Class B

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

4.00%

^[2]

Management fees

rr_ManagementFeesOverAssets

0.73%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.29%

Total annual fund operating expenses

rr_ExpensesOverAssets

2.02%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

2.02%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

605

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

909

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,313

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,155

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

205

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

634

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,088

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

2,155

1 Year

rr_AverageAnnualReturnYear01

10.45%

5 Years

rr_AverageAnnualReturnYear05

5.30%

10 Years

rr_AverageAnnualReturnYear10

9.57%

(Delaware Select Growth Fund) | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

^[2]

Management fees

rr_ManagementFeesOverAssets

0.73%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.29%

Total annual fund operating expenses

rr_ExpensesOverAssets

2.02%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

2.02%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

305

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

634

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,088

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,348

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

205

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

634

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,088

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

2,348

1 Year

rr_AverageAnnualReturnYear01

13.48%

5 Years

rr_AverageAnnualReturnYear05

5.66%

10 Years

rr_AverageAnnualReturnYear10

9.42%

(Delaware Select Growth Fund) | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.73%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.60%

Other expenses

rr_OtherExpensesOverAssets

0.29%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.62%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.10%)

^[3]

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

1.52%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

155

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

501

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

872

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,914

Label

rr_AverageAnnualReturnLabel

(lifetime:6/2/03–12/31/12)

1 Year

rr_AverageAnnualReturnYear01

15.02%

5 Years

rr_AverageAnnualReturnYear05

6.18%

Lifetime

rr_AverageAnnualReturnSinceInception

8.13%

(Delaware Select Growth Fund) | Institutional Class

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.73%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.29%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.02%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

1.02%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

104

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

325

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

563

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,248

1 Year

rr_AverageAnnualReturnYear01

15.60%

5 Years

rr_AverageAnnualReturnYear05

6.73%

10 Years

rr_AverageAnnualReturnYear10

10.52%

(Delaware Large Cap Core Fund)

Risk/Return:

rr_RiskReturnAbstract

Objective [Heading]

rr_ObjectiveHeading

What is the Fund's investment objective?

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Delaware Large Cap Core Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

What are the Fund's fees and expenses?

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Investments® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

The Fund's investment manager, Delaware Management Company (Manager), is voluntarily waiving its investment advisory fees and/or paying expenses (excluding any 12b-1 fees, taxes, interest, short sale and dividend interest expenses, brokerage fees, certain insurance costs, and nonroutine expenses or costs, including, but not limited to, those relating to reorganizations, litigation, conducting shareholder meetings, and liquidations) to the extent necessary to prevent total annual Fund operating expenses from exceeding 0.95% of the Fund's average daily net assets from August 28, 2013 until such time as the voluntary expense cap is discontinued. In addition, the Fund's distributor, Delaware Distributor, L.P. (Distributor), has voluntarily agreed to waive all 12b-1 fees. After giving effect to the Manager's and Distributor's voluntary waivers, the total net annual Fund's operating expenses for the Fund's Class A, Class C, Class R, and Institutional Class shares are 0.95%. The Manager's and Distributor's waivers and/or reimbursements may be discontinued at any time because they are voluntary.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 21% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

21.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Investments® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

50,000

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

What are the Fund's principal investment strategies?

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund's investment manager, Delaware Management Company (Manager), will invest the Fund's assets primarily in common stocks of large companies that the Manager believes have a combination of attractive valuations, growth prospects, and strong cash flows. Under normal circumstances, the Fund will invest at least 80% of its net assets in securities of large-capitalization companies (80% policy). The Fund currently defines large-capitalization companies as those that, at the time of investment, have market capitalizations within the range of market capitalizations of companies in the S&P 500® Index. While the market capitalization of companies in the S&P 500 Index ranged from approximately $2 billion to $402 billion as of June 30, 2013, the Fund will normally invest in common stock of companies with market capitalizations of at least $2 billion at the time of purchase. The Fund's 80% policy can be changed without shareholder approval. However, shareholders would be given at least 60 days' notice prior to any change.

Risk [Heading]

rr_RiskHeading

What are the principal risks of investing in the Fund?

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio. Principal risks include:

Investments not guaranteed by Delaware Management Company (Manager) or its affiliates — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Foreign risk — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Futures and options risk — The possibility that a fund may experience a loss if it employs an options or futures strategy related to a security or a market index and that security or index moves in the opposite direction from what the portfolio manager anticipated. Futures and options also involve additional expenses (such as the payment of premiums), which could reduce any benefit or increase any loss that a fund gains from using the strategy.

Counterparty risk — The risk that a counterparty to a derivative contract (such as a futures or options contract) or a repurchase agreement may fail to perform its obligations under the contract or agreement due to financial difficulties (such as a bankruptcy or reorganization).

Liquidity risk — The possibility that securities cannot be readily sold within seven days at approximately the price at which a portfolio has valued them.

Government and regulatory risk — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

Risk Lose Money [Text]

rr_RiskLoseMoney

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

How has Delaware Large Cap Core Fund performed?

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns for the 1-year, 5-year, and lifetime 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 it will perform in the future. The returns reflect expense caps in effect during these periods. The returns would be lower without the expense caps. You may obtain the Fund's most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800 523-1918

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

delawareinvestments.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Year-by-year total return (Class A)

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

As of June 30, 2013, the Fund's Class A shares had a calendar year-to-date return of 12.31%. During the periods illustrated in this bar chart, Class A's highest quarterly return was 15.91% for the quarter ended June 30, 2009 and its lowest quarterly return was -21.71% for the quarter ended Dec. 31, 2008. 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 sales charge were included, the returns would be less than those shown. The average annual returns in the table below do include the sales charge.

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns for periods ended December 31, 2012

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

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

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns are not relevant for shares held in tax-deferred investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs).

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax performance is presented only for Class A shares of the Fund.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

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-deferred 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.

(Delaware Large Cap Core Fund) | S&P 500 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

Lifetime (8/31/06 to 12/31/12)

1 Year

rr_AverageAnnualReturnYear01

16.00%

5 Years

rr_AverageAnnualReturnYear05

1.66%

Lifetime

rr_AverageAnnualReturnSinceInception

3.63%

(Delaware Large Cap Core Fund) | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.65%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

1.42%

Total annual fund operating expenses

rr_ExpensesOverAssets

2.32%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

797

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

1,258

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,744

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

3,078

Annual Return 2007

rr_AnnualReturn2007

7.73%

Annual Return 2008

rr_AnnualReturn2008

(36.77%)

Annual Return 2009

rr_AnnualReturn2009

23.62%

Annual Return 2010

rr_AnnualReturn2010

11.93%

Annual Return 2011

rr_AnnualReturn2011

2.41%

Annual Return 2012

rr_AnnualReturn2012

15.05%

Year to Date Return, Label

rr_YearToDateReturnLabel

As of June 30, 2013, the Fund's Class A shares had a calendar year-to-date return of 12.31%

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jun. 30, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

12.31%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Class A's highest quarterly return was 15.91% for the quarter ended June 30, 2009

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

15.91%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest quarterly return was -21.71% for the quarter ended Dec. 31, 2008

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(21.71%)

Label

rr_AverageAnnualReturnLabel

Lifetime (8/31/06 to 12/31/12)

1 Year

rr_AverageAnnualReturnYear01

8.48%

5 Years

rr_AverageAnnualReturnYear05

(0.57%)

Lifetime

rr_AverageAnnualReturnSinceInception

1.96%

(Delaware Large Cap Core Fund) | Class A | return after taxes on distributions

Risk/Return:

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

Lifetime (8/31/06 to 12/31/12)

1 Year

rr_AverageAnnualReturnYear01

8.33%

5 Years

rr_AverageAnnualReturnYear05

(0.71%)

Lifetime

rr_AverageAnnualReturnSinceInception

1.68%

(Delaware Large Cap Core Fund) | Class A | return after taxes on distributions and sale of Fund shares

Risk/Return:

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

Lifetime (8/31/06 to 12/31/12)

1 Year

rr_AverageAnnualReturnYear01

5.71%

5 Years

rr_AverageAnnualReturnYear05

(0.51%)

Lifetime

rr_AverageAnnualReturnSinceInception

1.61%

(Delaware Large Cap Core Fund) | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

^[1]

Management fees

rr_ManagementFeesOverAssets

0.65%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

1.42%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.07%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

410

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

948

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,611

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

3,383

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

310

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

948

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,611

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

3,383

Label

rr_AverageAnnualReturnLabel

Lifetime (8/31/06 to 12/31/12)

1 Year

rr_AverageAnnualReturnYear01

5 Years

rr_AverageAnnualReturnYear05

Lifetime

rr_AverageAnnualReturnSinceInception

(Delaware Large Cap Core Fund) | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.65%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.60%

Other expenses

rr_OtherExpensesOverAssets

1.42%

Total annual fund operating expenses

rr_ExpensesOverAssets

2.67%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

270

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

829

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,415

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

3,003

Label

rr_AverageAnnualReturnLabel

Lifetime (8/31/06 to 12/31/12)

1 Year

rr_AverageAnnualReturnYear01

5 Years

rr_AverageAnnualReturnYear05

Lifetime

rr_AverageAnnualReturnSinceInception

(Delaware Large Cap Core Fund) | Institutional Class

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.65%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

1.42%

Total annual fund operating expenses

rr_ExpensesOverAssets

2.07%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

210

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

649

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,114

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,400

Label

rr_AverageAnnualReturnLabel

Lifetime (8/31/06 to 12/31/12)

1 Year

rr_AverageAnnualReturnYear01

15.05%

5 Years

rr_AverageAnnualReturnYear05

0.61%

Lifetime

rr_AverageAnnualReturnSinceInception

2.92%

[1] Class C shares redeemed within one year of purchase are subject to a 1.00% contingent deferred sales charge (CDSC).

[2] If you redeem Class B shares during the first year after you buy them, you will pay a contingent deferred sales charge (CDSC) of 4.00%, which declines to 3.25% during the second year, 2.75% during the third year, 2.25% during the fourth and fifth years, 1.50% during the sixth year, and 0% thereafter. Class C shares redeemed within one year of purchase are subject to a 1.00% CDSC.

[3] The Fund's distributor, Delaware Distributors, L.P. (Distributor), has contracted to limit the Class R shares' 12b-1 fees to no more than 0.50% of the Fund's average daily net assets from August 28, 2013 through February 27, 2015 or, if longer, until the Fund is offered to all new investors (as described under "Purchase and redemption of Fund shares").

XML

(Delaware Select Growth Fund)

What is the Fund's investment objective?

Delaware Select Growth Fund seeks long-term capital appreciation.

What are the Fund's fees and expenses?

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Investments® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

Shareholder fees (fees paid directly from your investment)

Shareholder Fees (Delaware Select Growth Fund)	Class A	Class B		Class C		Class R	Institutional Class
Maximum sales charge (load) imposed on purchases as a percentage of offering price	5.75%	none		none		none	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none	4.00%	[1]	1.00%	[1]	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses (Delaware Select Growth Fund)	Class A	Class B	Class C	Class R		Institutional Class
Management fees	0.73%	0.73%	0.73%	0.73%		0.73%
Distribution and service (12b-1) fees	0.25%	1.00%	1.00%	0.60%		none
Other expenses	0.29%	0.29%	0.29%	0.29%		0.29%
Total annual fund operating expenses	1.27%	2.02%	2.02%	1.62%		1.02%
Fee waivers and expense reimbursements				(0.10%)	[1]
Total annual fund operating expenses after fee waivers and expense reimbursements	1.27%	2.02%	2.02%	1.52%		1.02%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. For Class R shares, this example reflects the net operating expenses with the Rule 12b-1 fee waiver for the contractual period and the total operating expenses without waivers for years 2 through 10. For Class A, Class B, Class C, and Institutional Class shares, this example assumes that the Fund's total operating expenses remain unchanged in each of the periods shown. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (Delaware Select Growth Fund) (USD $)	1 Year	3 Years	5 Years	10 Years
Class A	697	955	1,232	2,021
Class B	605	909	1,313	2,155
Class C	305	634	1,088	2,348
Class R	155	501	872	1,914
Institutional Class	104	325	563	1,248

Expense Example, No Redemption (Delaware Select Growth Fund) (USD $)	1 Year	3 Years	5 Years	10 Years
Class B	205	634	1,088	2,155
Class C	205	634	1,088	2,348

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 38% of the average value of its portfolio.

What are the Fund's principal investment strategies?

The Fund invests primarily in common stocks of companies that we believe have long-term capital appreciation potential and are expected to grow faster than the U.S. economy. The portfolio managers will consider companies of any size or market capitalization. Using a bottom-up approach, the portfolio managers seek to select securities they believe have large end-market potential or dominance of a profitable niche market, dominant business models, and strong free cash flow generation that are attractively priced compared to the intrinsic value of the securities. They also consider a company's operational efficiencies, management's plans for capital allocation, and the company's shareholder orientation. Holdings are generally sold for the following reasons: a better idea is found (that is, the stock is "crowded out" of the portfolio); an unexpected, negative fundamental change, including change in investment strategy; the holding's valuation becomes stretched past fair value; or portfolio construction considerations.

What are the principal risks of investing in the Fund?

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio. Principal risks include:

Investments not guaranteed by Delaware Management Company (Manager) or its affiliates — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Issuer concentration risk — The portfolio generally holds 40 to 60 securities although, from time to time, the portfolio may hold fewer or more securities depending on our assessment of the investment opportunities available. This allows us to focus on the potential of those particular issuers, but it also means that the Fund may be more volatile than those funds that hold a greater number of securities.

Company size risk — The risk that prices of small- and medium-sized companies may be more volatile than those of larger companies because of limited financial resources or dependence on narrow product lines.

Liquidity risk — The possibility that securities cannot be readily sold within seven days at approximately the price at which a portfolio has valued them.

Foreign risk — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Currency risk — The risk that the value of a portfolio's investments may be negatively affected by changes in foreign currency exchange rates.

Interest rate risk — The risk that securities will decrease in value if interest rates rise. The risk is generally associated with bonds; however, because small- and medium-sized companies and companies in the real estate sector often borrow money to finance their operations, they may be adversely affected by rising interest rates.

Counterparty risk — The risk that a counterparty to a derivative contract (such as a swap, futures, or options contract) or a repurchase agreement may fail to perform its obligations under the contract or agreement due to financial difficulties (such as a bankruptcy or reorganization).

Government and regulatory risk — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

How has Delaware Select Growth Fund performed?

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns for the 1-, 5-, and 10-year or lifetime 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 it will perform in the future. The returns reflect expense caps in effect during certain of these periods. The returns would be lower without the expense caps. You may obtain the Fund's most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

Year-by-year total return (Class A)

As of June 30, 2013, the Fund's Class A shares had a calendar year-to-date return of 9.22%. During the periods illustrated in this bar chart, Class A's highest quarterly return was 23.21% for the quarter ended June 30, 2009 and its lowest quarterly return was -24.96% for the quarter ended December 31, 2008. 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 sales charge were included, the returns would be less than those shown. The average annual returns in the table below do include the sales charge.

Average annual total returns for periods ended December 31, 2012

Average Annual Total Returns (Delaware Select Growth Fund)	Label	1 Year	5 Years	10 Years	Lifetime
Class A		8.68%	5.20%	9.58%
Class A return after taxes on distributions		8.68%	5.20%	9.58%
Class A return after taxes on distributions and sale of Fund shares		5.64%	4.49%	8.56%
Class B		10.45%	5.30%	9.57%
Class C		13.48%	5.66%	9.42%
Class R	(lifetime:6/2/03–12/31/12)	15.02%	6.18%		8.13%
Institutional Class		15.60%	6.73%	10.52%
Russell 3000® Growth Index (reflects no deduction for fees, expenses, or taxes)		15.20%	3.15%	7.69%

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-deferred 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.

(Delaware Large Cap Core Fund)

What is the Fund's investment objective?

Delaware Large Cap Core Fund seeks long-term capital appreciation.

What are the Fund's fees and expenses?

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Investments® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

The Fund's investment manager, Delaware Management Company (Manager), is voluntarily waiving its investment advisory fees and/or paying expenses (excluding any 12b-1 fees, taxes, interest, short sale and dividend interest expenses, brokerage fees, certain insurance costs, and nonroutine expenses or costs, including, but not limited to, those relating to reorganizations, litigation, conducting shareholder meetings, and liquidations) to the extent necessary to prevent total annual Fund operating expenses from exceeding 0.95% of the Fund's average daily net assets from August 28, 2013 until such time as the voluntary expense cap is discontinued. In addition, the Fund's distributor, Delaware Distributor, L.P. (Distributor), has voluntarily agreed to waive all 12b-1 fees. After giving effect to the Manager's and Distributor's voluntary waivers, the total net annual Fund's operating expenses for the Fund's Class A, Class C, Class R, and Institutional Class shares are 0.95%. The Manager's and Distributor's waivers and/or reimbursements may be discontinued at any time because they are voluntary.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees (Delaware Large Cap Core Fund)	Class A	Class C		Class R	Institutional Class
Maximum sales charge (load) imposed on purchases as a percentage of offering price	5.75%	none		none	none
Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower	none	1.00%	[1]	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses (Delaware Large Cap Core Fund)	Class A	Class C	Class R	Institutional Class
Management fees	0.65%	0.65%	0.65%	0.65%
Distribution and service (12b-1) fees	0.25%	1.00%	0.60%	none
Other expenses	1.42%	1.42%	1.42%	1.42%
Total annual fund operating expenses	2.32%	3.07%	2.67%	2.07%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (Delaware Large Cap Core Fund) (USD $)	1 Year	3 Years	5 Years	10 Years
Class A	797	1,258	1,744	3,078
Class C	410	948	1,611	3,383
Class R	270	829	1,415	3,003
Institutional Class	210	649	1,114	2,400

Expense Example, No Redemption (Delaware Large Cap Core Fund) (USD $)	1 Year	3 Years	5 Years	10 Years
Class C	310	948	1,611	3,383

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 21% of the average value of its portfolio.

What are the Fund's principal investment strategies?

The Fund's investment manager, Delaware Management Company (Manager), will invest the Fund's assets primarily in common stocks of large companies that the Manager believes have a combination of attractive valuations, growth prospects, and strong cash flows. Under normal circumstances, the Fund will invest at least 80% of its net assets in securities of large-capitalization companies (80% policy). The Fund currently defines large-capitalization companies as those that, at the time of investment, have market capitalizations within the range of market capitalizations of companies in the S&P 500® Index. While the market capitalization of companies in the S&P 500 Index ranged from approximately $2 billion to $402 billion as of June 30, 2013, the Fund will normally invest in common stock of companies with market capitalizations of at least $2 billion at the time of purchase. The Fund's 80% policy can be changed without shareholder approval. However, shareholders would be given at least 60 days' notice prior to any change.

What are the principal risks of investing in the Fund?

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio. Principal risks include:

Investments not guaranteed by Delaware Management Company (Manager) or its affiliates — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Foreign risk — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Futures and options risk — The possibility that a fund may experience a loss if it employs an options or futures strategy related to a security or a market index and that security or index moves in the opposite direction from what the portfolio manager anticipated. Futures and options also involve additional expenses (such as the payment of premiums), which could reduce any benefit or increase any loss that a fund gains from using the strategy.

Counterparty risk — The risk that a counterparty to a derivative contract (such as a futures or options contract) or a repurchase agreement may fail to perform its obligations under the contract or agreement due to financial difficulties (such as a bankruptcy or reorganization).

Liquidity risk — The possibility that securities cannot be readily sold within seven days at approximately the price at which a portfolio has valued them.

Government and regulatory risk — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

How has Delaware Large Cap Core Fund performed?

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns for the 1-year, 5-year, and lifetime 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 it will perform in the future. The returns reflect expense caps in effect during these periods. The returns would be lower without the expense caps. You may obtain the Fund's most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

Year-by-year total return (Class A)

As of June 30, 2013, the Fund's Class A shares had a calendar year-to-date return of 12.31%. During the periods illustrated in this bar chart, Class A's highest quarterly return was 15.91% for the quarter ended June 30, 2009 and its lowest quarterly return was -21.71% for the quarter ended Dec. 31, 2008. 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 sales charge were included, the returns would be less than those shown. The average annual returns in the table below do include the sales charge.

Average annual total returns for periods ended December 31, 2012

Average Annual Total Returns (Delaware Large Cap Core Fund)	Label	1 Year	5 Years	Lifetime
Class A	Lifetime (8/31/06 to 12/31/12)	8.48%	(0.57%)	1.96%
Class A return after taxes on distributions	Lifetime (8/31/06 to 12/31/12)	8.33%	(0.71%)	1.68%
Class A return after taxes on distributions and sale of Fund shares	Lifetime (8/31/06 to 12/31/12)	5.71%	(0.51%)	1.61%
Class C	Lifetime (8/31/06 to 12/31/12)
Class R	Lifetime (8/31/06 to 12/31/12)
Institutional Class	Lifetime (8/31/06 to 12/31/12)	15.05%	0.61%	2.92%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	Lifetime (8/31/06 to 12/31/12)	16.00%	1.66%	3.63%

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-deferred 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.

[1] If you redeem Class B shares during the first year after you buy them, you will pay a contingent deferred sales charge (CDSC) of 4.00%, which declines to 3.25% during the second year, 2.75% during the third year, 2.25% during the fourth and fifth years, 1.50% during the sixth year, and 0% thereafter. Class C shares redeemed within one year of purchase are subject to a 1.00% CDSC.

[1] The Fund's distributor, Delaware Distributors, L.P. (Distributor), has contracted to limit the Class R shares' 12b-1 fees to no more than 0.50% of the Fund's average daily net assets from August 28, 2013 through February 27, 2015 or, if longer, until the Fund is offered to all new investors (as described under "Purchase and redemption of Fund shares").

[1] Class C shares redeemed within one year of purchase are subject to a 1.00% contingent deferred sales charge (CDSC).