v3.8.0.1
DEI Document - shares
3 Months Ended
Mar. 31, 2018
Apr. 30, 2018
Document Information [Abstract]    
Entity Registrant Name NuStar Energy L.P.  
Entity Central Index Key 0001110805  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Mar. 31, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q1  
Trading Symbol ns  
Amendment Flag false  
Entity Partnership Units Outstanding   93,183,029