Percentage of voting equity interests acquired at the acquisition date in the business combination.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
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 units or percentage investment held by one or more members or limited partners of the LLC or LP.

+ References

+ Details

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

- Details

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

- Details

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

- Details

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

Significant Accounting Policies (Details 5)	0 Months Ended	6 Months Ended	12 Months Ended		0 Months Ended
Significant Accounting Policies (Details 5)	May 17, 2011	Sep. 30, 2014	Mar. 31, 2014	Mar. 31, 2013	Jul. 02, 2014
Noncontrolling Interests
Limited partners, interest (as a percent)		99.90%	99.90%	99.90%
General partner, interest (as a percent)	0.10%	0.10%	0.10%	0.10%
TLP
Noncontrolling Interests
Ownership interest acquired (as a percent)					19.70%
TLP
Noncontrolling Interests
Limited partners, interest (as a percent)					98.00%
General partner, interest (as a percent)					2.00%