XML 13 R1.htm IDEA: XBRL DOCUMENT v3.5.0.2
Document and Entity Information - shares
9 Months Ended
Oct. 31, 2016
Dec. 01, 2016
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Oct. 31, 2016  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q3  
Trading Symbol MENT  
Entity Registrant Name MENTOR GRAPHICS CORP  
Entity Central Index Key 0000701811  
Current Fiscal Year End Date --01-31  
Entity Filer Category Large Accelerated Filer  
Common Stock, Shares, Outstanding   109,521,738