v3.19.3.a.u2
DEI Document - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2019
Jan. 31, 2020
Jun. 28, 2019
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2019    
Document Transition Report false    
Entity File Number 1-16417    
Entity Registrant Name NUSTAR ENERGY L.P.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 74-2956831    
Entity Address, Address Line One 19003 IH-10 West    
Entity Address, City or Town San Antonio    
Entity Address, State or Province TX    
Entity Address, Postal Zip Code 78257    
City Area Code (210)    
Local Phone Number 918-2000    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 2.7
Entity Partnership Units Outstanding   108,527,939  
Entity Central Index Key 0001110805    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false    
Common Limited Partner [Member]      
Document Information [Line Items]      
Title of 12(b) Security Common units    
Trading Symbol NS    
Security Exchange Name NYSE    
Series A Preferred Limited Partner [Member]      
Document Information [Line Items]      
Title of 12(b) Security Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units    
Trading Symbol NSprA    
Security Exchange Name NYSE    
Series B Preferred Limited Partner [Member]      
Document Information [Line Items]      
Title of 12(b) Security Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units    
Trading Symbol NSprB    
Security Exchange Name NYSE    
Series C Preferred Limited Partner [Member]      
Document Information [Line Items]      
Title of 12(b) Security Series C Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units    
Trading Symbol NSprC    
Security Exchange Name NYSE