v2.4.0.8

SEGMENT INFORMATION Narrative (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenue, Major Customer [Line Items]
Entity-Wide Revenue, Major Customer, Percent of Total Revenues	15.00%	11.00%	11.00%
Entity-Wide Revenue, Major Customer, Amount	$ 534.2	$ 668.1	$ 684.1

X

- Definition

Percent of revenue generated from a single external customer that accounts for 10 percent or more of an entity's revenues.

+ References

No definition available.

+ Details

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

X

- Details

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

X

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration