UNIT-BASED COMPENSATION (Non-cash Compensation Expense) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
DFW Net Profits Interests
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Non-cash compensation expense (in dollars) $ 17 $ 688 $ 2,171
SMP Net Profits Interests
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Non-cash compensation expense (in dollars) $ 919 $ 1,269