UNIT-BASED COMPENSATION Table 3 (Details) (The 2006 LTIP [Member], Unit Options [Member], USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
The 2006 LTIP [Member] \| Unit Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance of NSH unit options outstanding	300,766	312,433
Weighted-average exercise price, unit options outstanding	$ 31.55
Weighted-average remaining contractual term in years, unit options outstanding	1 year 11 months 15 days
Aggregate intrinsic value, unit options outstanding	$ 0
Balance of NSH unit options exercisable	300,766
Weighted-average exercise price, unit options exercisable	$ 31.55
Weighted-average remaining contractual term in years, unit options exercisable	1 year 11 months 15 days
Aggregate intrinsic value, unit options exercisable	$ 0

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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