v3.21.1

CONSOLIDATED STATEMENTS OF PARTNERS' EQUITY AND MEZZANINE EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Common Limited Partner [Member]
Cash distributions paid, per unit	$ 0.40	$ 0.60

X

- Definition

Per unit of ownership amount of cash distributions paid to unit-holder of a limited partnership (LP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerDistributionsPaidPerUnit
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=ns_CommonLimitedPartnerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: