MEMBERS' EQUITY Table 3 (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Our cash distributions applicable to the period in which the distributions were earned
Cash distributions per unit	$ 0.545	$ 0.545	$ 0.545	$ 0.545	$ 1.090	$ 1.090
Total cash distributions	$ 23,250	$ 23,248	$ 23,249	$ 23,236	$ 46,498	$ 46,458

Distribution amount per limited liability company member unit outstanding earned during the period, and to be paid in the subsequent quarter.

No definition available.

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Namespace Prefix:	nsh_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration