The vessels' capacity in twenty-foot equivalent unit (TEU).

No definition available.

Name:	NMM_ContainershipCapacity
Namespace Prefix:	NMM_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual right on the sale price of an asset agreed in a Memorandum of Agreement.

+ References

No definition available.

+ Details

Name:	NMM_SalePriceContractualAgreement
Namespace Prefix:	NMM_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The year that the vessel was built.

+ References

No definition available.

+ Details

Name:	NMM_VesselYearBuilt
Namespace Prefix:	NMM_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of contractual obligation due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_ContractualObligationDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The increase (decrease) during the reporting period in monies given as security or collateral for items acquired or borrowed on a temporary basis. Deposits may also be paid as initial payment of the cost of acquisition or for the right to enter into a contract or agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

+ Details

Name:	us-gaap_IncreaseDecreaseInDepositsOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of noncurrent assets classified as other.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_OtherAssetsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

Name:	us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LongtermDebtTypeAxis=NMM_RefinanceJuly2012CreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=NMM_DrybulkVesselsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=NMM_YMUnityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=NMM_YMUtmostMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=NMM_YmUnityAndYmUtmostMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingencies (Details) $ in Thousands	4 Months Ended	6 Months Ended
Commitments and Contingencies (Details) $ in Thousands	Apr. 27, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Property Plant And Equipment [Line Items]
Other long-term assets		$ 2,793		$ 2,779
Deposits for vessels acquisitions		14	$ 0
Contractual obligation		22,970
Refinance of July 2012 Credit Facility
Property Plant And Equipment [Line Items]
Contractual obligation		20,200
One Drybulk Carrier Vessel
Property Plant And Equipment [Line Items]
Other long-term assets				$ 2,770
Deposits for vessels acquisitions		$ 2,770
YM Unity
Property Plant And Equipment [Line Items]
Vessel Year Built		2006
Containership Capacity		8,204
YM Utmost
Property Plant And Equipment [Line Items]
Vessel Year Built		2006
Containership Capacity		8,204
YM Unity and YM Utmost
Property Plant And Equipment [Line Items]
Sale Price Contractual Agreement	$ 67,000