Load [Member] Shareholder Fees - North Carolina Tax-Free Income Series - North Carolina Tax-Free Income Series	Jun. 30, 2026 USD ($)
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage)	0.00%
Redemption Fee (as a percentage of Amount Redeemed)	0.00%
Redemption Fee	$ (15.00)
Exchange Fee (as a percentage of Amount Redeemed)	0.00%
Maximum Account Fee (as a percentage of Assets)	0.00%
Load [Member]
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 2

Name:	oef_ExchangeFeeOverRedemption
Namespace Prefix:	oef_
Data Type:	oef:nonNegativePure4ItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 2

Name:	oef_MaximumAccountFeeOverAssets
Namespace Prefix:	oef_
Data Type:	oef:nonNegativePure4ItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 2

Name:	oef_MaximumDeferredSalesChargeOverOther
Namespace Prefix:	oef_
Data Type:	oef:nonNegativePure4ItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 2

Name:	oef_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice
Namespace Prefix:	oef_
Data Type:	oef:nonNegativePure4ItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 1
-Subsection a

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 2

Name:	oef_RedemptionFee
Namespace Prefix:	oef_
Data Type:	oef:nonPositiveMonetaryItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 2

Name:	oef_RedemptionFeeOverRedemption
Namespace Prefix:	oef_
Data Type:	oef:nonPositivePure4ItemType
Balance Type:	na
Period Type:	duration

Name:	dei_LegalEntityAxis=dmf_S000012002Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_DocumentInformationDocumentAxis=dmf_LoadMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: