Represents the number of terminals owned by the entity.

No definition available.

Name:	ngl_NumberOfOwnedTerminals
Namespace Prefix:	ngl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

Name:	us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ngl_TransMontaignePartnersLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ngl_CrudeOilLogisticsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ngl_RefinedProductsAndRenewablesSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ngl_RetailPropaneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Organization and Operations (Details)	0 Months Ended	6 Months Ended	12 Months Ended
Organization and Operations (Details)	May 17, 2011	Sep. 30, 2014	Mar. 31, 2014	Mar. 31, 2013
Organization and operations
Equity method ownership interest (as a percent)			50.00%
Ownership interest (as a percent)	0.10%	0.10%	0.10%	0.10%
TLP \| General partner
Organization and operations
Ownership interest (as a percent)		2.00%
TLP \| Limited partner
Organization and operations
Ownership interest (as a percent)		19.70%
Retail propane and distillate operations
Organization and operations
Number of owned terminals		22	22
Retail propane and distillate operations \| Minimum
Organization and operations
Number of states in which entity operates		20	20
Refined products and renewables \| BOSTCO
Organization and operations
Equity method ownership interest (as a percent)		42.50%
Refined products and renewables \| Frontera
Organization and operations
Equity method ownership interest (as a percent)		50.00%
Crude oil logistics
Organization and operations
Equity method ownership interest (as a percent)		50.00%