XML 22 R1.htm IDEA: XBRL DOCUMENT v2.4.0.8
Document and Entity Information
9 Months Ended
Sep. 30, 2014
Oct. 30, 2014
Entity Information [Line Items]    
Entity registrant name Northwest Pipeline LLC  
Entity central index key 0000110019  
Document type 10-Q  
Document period end date Sep. 30, 2014  
Amendment flag false  
Document fiscal year focus 2014  
Document fiscal period focus Q3  
Current fiscal year end date --12-31  
Entity filer category Non-accelerated Filer  
Entity common stock, shares outstanding   0