Document and Entity Information
3 Months Ended
Mar. 31, 2018
Document And Entity Information [Abstract]  
Entity Registrant Name UNISYS CORP
Trading Symbol UIS
Entity Central Index Key 0000746838
Current Fiscal Year End Date --12-31
Entity Filer Category Accelerated Filer
Document Type 10-Q
Document Period End Date Mar. 31, 2018
Document Fiscal Year Focus 2018
Document Fiscal Period Focus Q1
Amendment Flag false
Entity Common Stock, Shares Outstanding 50,964,531