v3.8.0.1

Certain Relationships and Related Party Transactions (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) $ / mo	Dec. 31, 2016 USD ($)
Related Party Transaction [Line Items]
Managing general partner maximum subordination percentage of share of net production revenues	50.00%
Subordination		$ 0
MGP
Related Party Transaction [Line Items]
Subordination target return rate for limited partner subscriptions	12.00%
Subordination target return rate for limited partner subscriptions for second, third and fourth twelve month period	10.00%
Subordination target return rate for limited partner subscriptions for last twelve month period	8.00%
Subordination		$ (188,000)
MGP and Affiliates \| General and administrative expenses
Related Party Transaction [Line Items]
Monthly administrative costs per well \| $ / mo	75
MGP and Affiliates \| Production
Related Party Transaction [Line Items]
Transportation fee rate as percentage of natural gas sales price	16.00%
Transportation fees (USD per Mcf)	$ 0.35
MGP and Affiliates \| Production \| Marcellus wells
Related Party Transaction [Line Items]
Monthly supervision fees per well \| $ / mo	975

Managing general partner maximum subordination percentage of share of net production revenues.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Monthly administrative costs per well.

+ References

No definition available.

+ Details

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Namespace Prefix:	pub09_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

- Definition

Monthly supervision fees per well.

+ References

No definition available.

+ Details

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Namespace Prefix:	pub09_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

- Definition

Under the terms of the Partnership Agreement, the MGP may be required to subordinate up to 50% of its share of net production revenues of the Partnership to provide a distribution to the limited partners equal to at least 10% of their agreed subscriptions. Subordination is determined on a cumulative basis, in each of the first five years of Partnership operations, commencing with the first distribution of net revenues to the limited partners.

+ References

No definition available.

+ Details

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Namespace Prefix:	pub09_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Subordination target return rate for limited partner subscriptions.

+ References

No definition available.

+ Details

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Namespace Prefix:	pub09_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Subordination Target Return Rate For Limited Partner Subscriptions For Last Twelve Month Period

+ References

No definition available.

+ Details

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Namespace Prefix:	pub09_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Subordination Target Return Rate For Limited Partner Subscriptions For Second, Third and Fourth Twelve Month Period

+ References

No definition available.

+ Details

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Namespace Prefix:	pub09_
Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Transportation fee rate as percentage of natural gas sales price.

+ References

No definition available.

+ Details

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Namespace Prefix:	pub09_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Transportation Fees Rate

+ References

No definition available.

+ Details

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Namespace Prefix:	pub09_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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Namespace Prefix:
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Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=pub09_MarcellusWellsMember
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Balance Type:
Period Type:

DGOC Series 28, L.P. 10-K