XML 13 R1.htm IDEA: XBRL DOCUMENT v3.8.0.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2018
Apr. 27, 2018
Document and Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q1  
Trading Symbol HSBCUSA  
Entity Registrant Name HSBC USA INC /MD/  
Entity Central Index Key 0000083246  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   714
Entity Well-known Seasoned Issuer Yes  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes